This  book  is  DUB  on  the  last  date  stamped  below 


Abrasives  &  Abrasive  Wheels 

Their  Nature,    Manufacture   and   Use 


A    COMPLETE    TREATISE    ON 

THE    MANUFACTURE    AND    PRACTICAL    USE    OF 
ABRASIVES,  ABRASIVE  WHEELS  AND  GRINDING  OPERATIONS 

INCLUDING 

NATURAL  AND  ARTIFICIAL  ABRASIVES,  PRODUCTION  AND  PREP- 
ARATION OF  ABRASIVES,  GRITS,  GRADES  AND  BONDS,  SHARPEN- 
ING AND  GRINDING  STONES  AND  WHEELS,  TESTING  WHEELS 
FOR  EFFICIENCY,  TRUING,  REBUSHING  AND  INSTALLING 
WHEELS,  SAFETY  DEVICES,  AND  DUST-COLLECTING  SYSTEMS, 
COMPLETE  EXPOSITION  ON  SURFACE,  EXTERNAL  AND  INTERNAL 
GRINDING  AND  COMPREHENSIVE  DATA  COVERING  THE  PHYS- 
ICAL AND  CHEMICAL  NATURE  OF  ABRASIVES  IN  GENERAL 

BY 

FRED  B.  JACOBS 


A  PRACTICAL  HANDBOOK  FOR  ENGINEERS,  FACTORY  SUPERINTEN- 
DENTS, FOUNDRYMEN,  SHOP  FOREMEN  AND  MECHANICS  IN  GENERAL 

FULLY  ILLUSTRATED 


New  York 

The  Norman  W.  Henley  Publishing  Company 

2  West  45th  Street 

1919 


Copyrighted,   1919,  by 
The  Norman  W.  Henley  Publishing  Company 


Printed  in  U.  S.  A. 


Printing — Presswork  and  Binding  by 
Harper  &  Brothers,  New  York 


PREFACE 

THE  art  of  finishing  metals  by  abrasion  is  one  of  the 
oldest  mechanical  practices  in  existence,  dating  from 
the  time  prehistoric  man  discovered  that  he  could  fashion 
his  wood  and  bone  implements  by  rubbing  them  on  rocks  of  a 
gritty  nature. 

The  grindstone  is,  without  doubt,  the  oldest  form  of 
grinding  wheel  known.  With  the  early  development  of 
the  mechanical  arts,  it  was  discovered  that  a  sandstone  cut 
in  circular  shape  and  mounted  upon  a  revolving  shaft, 
showed  higher  efficiency  than  the  side  of  a  rock  for  sharpen- 
ing and  shaping  various  implements.  It  is  definitely  known 
that  grindstones,  rotated  by  power,  were  used  in  the  manu- 
facture of  armor  as  early  as  the  year  1570.  It  is  also 
known  that  the  emery  deposits  of  the  Grecian  Archipelago 
were  known  to  the  ancients  and  the  value  of  this  abrasive 
recognized,  as  many  writers  of  early  days  referred  to  emery 
under  various  names.  In  considering  some  of  the  mechan- 
ical achievements  of  the  handicraftsmen  who  worked  with 
metals  centuries  before  the  Christian  era,  it  is  hard  to 
conceive  how  they  attained  so  high  a  degree  of  perfection 
without  the  use  of  an  alumina  abrasive  for  tool-sharpening 
purposes. 

While  the  practice  of  fashioning  tools  and  implements  by 
abrasion  is  in  all  probability  as  old  as  civilization  itself, 
modern  grinding,  as  we  accept  this  term,  is  a  compara- 
tively recent  development.  About  half  a  century  ago, 
the  individual  workman  made  his  own  grinding  wheels  of 
glue  and  emery. 

The  first  attempt  at  precision  grinding  consisted  of  finish- 
ing the  chilled  iron  calender  rolls  used  in  the  paper-making 

5 


PREFACE 

industry.  Owing  to  the  hard  nature  of  the  material  in 
question,  it  was  a  long  and  tedious  process  to  turn  these 
rolls  accurately. 

The  development  of  the  sewing-machine  industry  in  the 
New  England  States  gave  impetus  to  the  development  of 
the  grinding-wheel  business.  As  a  matter  of  fact,  the  first 
attempts  at  cylindrical  grinding,  aside  from  roll  grinding, 
consisted  of  finishing  parts  of  the  Wilcox  &  Gibbs  sewing 
machine.  The  work  was  done  by  the  Brown  &  Sharpe 
Mfg.  Co. 

With  the  advent  of  the  automobile  industry,  over  twenty 
years  ago,  the  grinding-wheel  business  received  a  fresh 
impetus  as  a  rapid  means  was  in  demand  for  the  accurate 
finishing  of  parts. 

Today,  the  modern  grinding  wheel  is  among  the  most 
useful  of  modern  shop  accessories.  Without  it,  it  would  be 
impossible  to  maintain  the  present-day  standard  of  rapid 
production.  In  practically  every  line  of  metal  working, 
the  grinding  wheel  plays  an  important  part,  its  usefulness 
ranging  all  the  way  from  the  rough  grinding  of  castings  and 
forgings  to  the  finishing  of  accurate  surfaces,  both  plane  and 
cylindrical. 

In  presenting  this  work,  the  writer  has  taken  great 
precaution  to  make  sure  that  every  statement  is  authentic. 
Aside  from  knowledge  gained  through  many  years  as  a 
journeyman  machinist,  later  supplemented  with  several 
years'  experience  as  a  grinding-wheel  salesman,  many  months 
were  spent  in  collecting  data,  verifying  statements  and 
consulting  reliable  authorities,  both  in  this  country  and 
abroad. 

The  writer  is  indebted  to  the  following  manufacturers 
and  individuals  who  cheerfully  answered  numerous  letters 
and  supplied  valuable  data  and  photographs: 

Abrasive  Co.  The  Carborundum  Co. 

American  Emery  Wheel  Works  Chicago  Wheel  &  Mfg.  Co. 

The  Blanchard  Machine  Co.  The    Cincinnati   Milling    Machine 

Brown  &  Sharpe  Mfg.  Co.  Co. 

6 


PREFACE 


The  Cleveland  Stone  Co. 
Cortland  Grinding  Wheel  Corp. 
Detroit  Grinding  Wheel  Co. 
Diamond  Machine  Co. 
Parrel  Foundry  &  Machine  Co. 
Metal  &  Thermit  Corp. 
H.  G.  Hammett. 
Hampden  Corundum  Wheel  Co. 
The  Heald  Machine  Co. 
Frederick  S.  Jacobs,  data  on  axe- 
grinding.     ' 
Landis  Tool  Co. 

Manufacturers  Corundum  Co.,  Ltd. 
Minnesota  Mining  &  Mfg.  Co. 
Newton  Machine  Tool  Works. 
Norton  Co. 


Norton  Grinding  Co. 

Penton  Publishing  Co. 

Pittsburgh  Crushed  Steel  Co. 

Pratt  &  Whitney  Co. 

Fred  E.  Rogers,  editor  emeritus  of 

Machinery. 

Safety  Emery  Wheel  Works. 
Springfield  Grinding  Co. 
Springfield  Mfg.  Co. 
Sterling  Grinding  Wheel  Co. 
B.  F.  Sturtevant  Co. 
Superior  Corundum  Wheel  Co. 
United  States  Geological  Survey. 
Vitrified  Wheel  Co. 
Waltham  Grinding  Wheel  Co. 
Wardwell  Mfg.  Co. 


Permission  to  reprint  material  by  the  writer  which  had 
been  previously  published,  was  granted  by  the  following 
publishers : 

Penton  Publishing  Co.,  Marine  Review. 
McGraw  Hill  Co.,  American  Machinist. 
S.  S.  Smith  Co.,  The  Woodworker. 
W.  R.  C  Smith  Publishing  Co.,  Iron  Tradesman. 
Iron  Age  Co.,  The  Iron  Age. 

The  MacLean  Publishing  Co.,  Ltd.,  Canadian  Machinery. 
The  Mines  Publishing  Co.,  Ltd.,  publishers  of  The  Canadian  Mining 
Journal,  gave  permission  to  reprint  material  concerning  corundum. 


FRED  B.  JACOBS. 


June,  1919. 


CONTENTS 

CHAP.  PAGE 

PREFACE ix 

I.  NATURAL  ABRASIVE  SUBSTANCES Pages  13  to  36 

Nature  of  natural  abrasives — Where  found — History  of  natural 
abrasives — Commercial     application — Sandstone — Emery — Corun- 
dum —  Garnet  —  Diamond  —  Bort  diamond  —  Flint  —  Quartz — Nat- 
ural sharpening  stones — Arkansas — Washita — Hindustan — Tripoli 

— Pumice. 

II.  ARTIFICIAL  ABRASIVES Pages  37  to  64 

Various  artificial  abrasives — Their  physical  and  chemical  properties 

— Their  Commercial  application — Methods  and  processes  employed 
in  the  production  of  artificial  abrasives — Carborundum — Alundum 
— Aloxite — Boro-  C  arbone — Oxalumina — Adamite — Crystolon,  etc. 
Relative  hardness  and  abrasive  efficiency  of  various  materials — 
Artificial  production  of  precious  stones — Their  abrasive  properties 
— Other  artificial  abrasives  and  their  production — Experimental 
work — Electro-thermic  processes — Production  of  rouge  and  crocus 
— Diamonds  and  crushed  steel — Angular  grit. 

III.  THE  MANUFACTURE  OF  GRINDING  WHEELS   ....   Pages  65  to  82 
Composition  of  grinding  wheels — Desirable  and  undesirable  proper- 
ties— Bonds — Shellac — Rubber — Fusible  clays — Silicate  of  soda — 
Vitrified  wheels — Method  of  oroducing  vitrified  wheels — Puddled 
process — Pressed  process — Silicate  wheels — Shellac  wheels — Rubber 
wheels — Clay  bond  used  in  vitrified  wheels — Choice  of  bonding  ma- 
terial— Wheel-turning — Kiln   used — Heating   of   kiln   and   work — 
Cooling  of  kiln — Dressing  wheels — Bushing  wheels — Speed  tests  for 
wheels — Elastic  process — Rubber  process. 

IV.  ARTIFICIAL  SHARPENING  STONES Pages  83  to  87 

Properties  of  artificial  stones — Carborundum  stones — Method  of 
manufacture  —  Bond  —  Grit  —  Grade  —  Finishing  —  Combination 
stones — Carborundum  rubs. 

V.  GRITS  AND  GRADES  .    .    .    ; Pages  88  to  96 

Designation  of  grits  and  grades — Mixed  grits — Grits  of  abrasive     s 
papers — Standard  grades — Wheels — Relation  of  speed  to  grade  and 

grit — Wheel  speeds  for  various  operations. 
9 


CONTENTS 

CHAP. 

VI.  TESTING  WHEELS  FOR  EFFICIENCY Pages  97  to  114 

Selection  of  wheels — Improper  methods  of  testing — Practical  testing 
methods — Items  to  be  noted  in  a  wheel  test — How  to  figure  result — 
Formula  for  finding  volume  of  abrasive  material  in  a  wheel — General 
considerations — Wheel  tests. 

VII.  LABORATORY  TESTS Pages  115  to  122 

Apparatus  and  appliances  used — Limitations  of  laboratory  tests — 
Factors  to  be  considered — Laboratory  testing  machine — Data  for 

test — Work  used  in  testing. 

VIII.  GRINDING  WHEEL  vs.  GRINDSTONES Pages  123  to  128 

Advantages  of  natural  and  artificial  abrasive  used  in  wheels — Early 

use  of  grindstones — Special  work  •  where  grindstones  are  still  em- 
ployed— Action  of  grinding  wheel. 

IX.  THE  ECONOMIC  ADVANTAGE  OF  USING  LARGE  WHEELS  .  Pages  129  to  132 
Factors  to  be  considered  in  choosing  a  wheel — Comparative  price  of 
wheels  of  various  sizes — Advantage  of  large  wheels  in  certain  work 

— Why  large  wheels  are  more  efficient. 

X.  TRUING  DEVICES  FOR  GRINDING  WHEELS Pages  133  to  138 

Abrasive  action — Tools  used  in  truing  wheels — Use  of  bort  and 
carbonado  diamonds  in  tools — Getting  stones  in  tool — Procedure  in 
truing  wheels. 

XI.  RE-BUSHING  GRINDING  WHEELS Pages  139  to  141 

Methods  used  in  bushing  wheels — Tools  employed — Metals  used. 

XII.  SUGGESTIONS  TO  FOLLOW  IN  ORDERING  GRINDING  WHEELS 

Pages  142  to  144 

Information  to  be  given  with  grinding-wheel  order — Factor  govern- 
ing selection  of  wheels — How  to  determine  what  kind  of  a  wheel 
should  be  used — Ordering  special  wheels. 

XIII.  DESIGN  OF  DUST-COLLECTING  SYSTEMS    ....   Pages  145  to  150 
State  law  requirments — Design  of  wheel  hood — General  design — 
Size  of  exhaust  pipe  for  different  size  wheels — Elbows — Collars — 
Method    of     erection — Clean-out — Fan — Dust-collector — Exhaust 
systems. 

XIV.  SAFEGUARDING  GRINDING  WHEELS Pages  151  to  165 

Why  wheels  break — Cause  of  accidents — How  wheels  are  packed 

and  tested  before  leaving  factory — Wheel  speeds — Mounting  wheels 
properly — What  causes  wheels  to  burst — Safety  flanges — Work  rest 
— Wheel  guards — Grinding  on  small  wheels — Precautions  for  the 
workman. 

10 


CONTENTS 

CHAP. 

XV.  ABRASIVE  PAPERS  AND  CLOTHS Pages  166  to  175 

Abrasive  substances  used  in  making  abrasive  paper — History  of 
abrasive  paper — How  abrasive  paper  and  cloth  is  manufactured — 
Grades  of  abrasive  paper  and  cloth — Finding  percentage  of  iron  in 
garnet — Testing  garnet  paper — Paper  and  cloth  abrasive  discs-- 
Testing discs  for  efficiency. 

XVI.  SURFACE  GRINDING Pages  176  to  215 

Finishing  work  by  surface  grinding — Development  of  the  surface 
grinding     machine — Finishing     locomotive     guide     bars — Rotary 
grinding  fixture — Wheel  speeds — Cuts — Die  grinding — How   dies 

are  held — Grinding  punches — Care  of  wheels — Magnetic  chucks — 
Demagnetizes — Proper  wheel  selection  for  surface  grinding — Types 
of  surface-grinding  machines — Standard  wheel  list. 

XVII.  CYLINDRICAL  GRINDING Pages  216  to  242 

Cylindrical  grinders— Operation  of  grinders — Driving  devices  for 
work — Proper  wheel  speeds  for  various  metals  and  work — Traverse 
feed — Depth   of   cut — Roughing   and   finishing   cuts — Sparking — 
Backrest  and  steadyrests — Lubrication  of  work — Lubricating  com 
pounds  and  mixtures — Dressing  and  truing  wheels  while  on  the 
grinder — Chatter  marks  and   their  remedy — Selection   of  proper 
wheels  for  use  on  cylindrical  grinders — Universal  grinders — Grinding 
tapers — Various  operations  on  universal  grinder. 

XVIII.  INTERNAL  GRINDING Pages  243  to  262 

Internal  grinding  machines — Internal  grinding  on  universal  grinder 

— Setting  up  universal  grinder  for  internal  work — Grinding  double 
tapers — Automatic  grinders — Grinding  holes  in  spur  and  bevel  gears 
— Chucks — Wet  and  dry  grinding — Proper  speeds — Selection  of 
wheels — Operating  of  cylinder  grinders — Cylinder  grinding. 

XIX.  SPECIAL  GRINDING  OPERATIONS Pages  263  to  289 

Grinding  calender  rolls — Special  grinding  machines — Roll  grinders 

and  roll  grinding — Corrugating  flour-mill  rolls — Grinding  crank- 
shafts— Grinding  cam  shafts — Locomotive  valve  gears. 

XX.  CUTTER  SHARPENING Pages  290  to  307 

Machines  employed  for  cutter  grinding — Adjustments  and  attach- 
ments on  cutter  grinders — Grinding  spiral  cutters — General  opera- 
tion of  cutter  grinders — Selection  of  wheels — Speeds — Depth  of  cut. 

XXI.  SAW  SHARPENING Pages  308  to  321 

Band  saws  and  circular  saws — Operation  of  band-saw  sharpening 
machine — Sharpening  band  saws — Grinding  in  new  teeth — Care  of 
machine — Selection   of   wheels   for   saw   gumming — Machines   for 
sharpening  cold  saws — Sharpening  hack-saw  blades. 

ii 


CHAPTER   ONE 

NATURAL   ABRASIVE   SUBSTANCES 

Nature  of  natural  abrasives — Where  found — History  of  natural  abrasives 
— Commercial  application — Sandstone — Emery — Corundum — Garnet — 
Diamond — Bort  diamond — Flint — Quartz — Natural  sharpening  stones — 
Arkansas — Washita — Hindustan — Tripoli — Pumice. 

NATURAL  abrasives  are  being  found  in  many  parts  of 
the  world.  In  a  broad  sense,  the  list  includes  all 
minerals  capable  of  abrasive  action,  but  from  a  commercial 
point  of  view,  the  principal  natural  abrasives  are  sandstone, 
emery,  corundum  and  garnet.  The  diamond  is,  of  course, 
a  natural  abrasive;  indeed  it  is  the  hardest  of  all,  but  it  is 
needless  to  state  that  its  rarity  excludes  it  from  the  list  of 
commercial  abrasive  materials. 

SANDSTONE 

The  first  abrasive  to  be  used  in  the  form  of  a  wheel  was 
in  all  probability  sandstone.  The  use  of  a  revolving  stone 
for  sharpening  purposes  is  so  old  that  the  beginning  is 
lost  in  antiquity.  It  seems  reasonable  to  believe,  however, 
that  the  artificers  of  early  civilization  borrowed  the  idea 
of  a  revolving  sharpening  stone  from  the  crude  mills  used 
many  centuries  ago  for  the  grinding  of  grain. 

Sandstone  is  a  very  curious  mineral,  indeed,  as  it  consists 
of  uniform  grains  of  sand  (generally  quartz  with  a  small 
percentage  of  feldspar  and  mica)  firmly  cemented  together 
with  silica.  Some  varieties  of  sandstone,  the  Craigleith 
stones  used  in  the  cut-glass  industry  for  instance,  are  prac- 
tically pure  silica,  this  material  often  running  as  high  as 
98  per  cent.  Sandstone  is  found  in  many  parts  of  the 

13 


ABRASIVES  AND  ABRASIVE  WHEELS 

world  and  in  this  country  the  most  extensive  deposits  that 
are  worked  for  the  production  of  grindstones  are  in  Ohio 
and  Michigan.  The  Gray  Canyon  quarry  at  Amherst, 
Ohio,  is  classed  as  the  largest  quarry  in  the  world.  Sand- 
stones are  of  various  colors,  these  being  derived  from 
impurities  that  penetrated  the  mass  during  the  formative 
stage.  Pure  siliceous  stones  are  white,  or  pale  yellow  in 
cases  where  small  quantities  of  iron  oxide  are  present.  A 
red  tinge  is  generally  due  to  hematite,  yellow  to  limonite, 
green  to  glauconite,  gray  to  clay  and  shale,  and  black,  as 
observed  in  black  Graileith  stones  for  example,  to  manganese 
dioxide. 

The  average  layman  is  of  the  opinion  that  all  grindstones 
are  alike,  but  this  supposition  is  erroneous  for,  in  forming 
the  sandstone  of  which  the  grindstones  of  commerce  are 
made,  it  would  appear  that  Nature  anticipated  the  wants 
of  man  by  providing  not  only  several  grits  to  choose  from, 
but  several  grades  as  well.  To  insure  an  ample  supply 
of  grits  and  grades,  grindstone  manufacturers  generally 
control  holdings  in  various  localities. 

Before  the  advent  of  the  grinding  wheel,  sandstone  was 
the  only  abrasive  to  be  used  in  the  form  of  a  wheel.  Its 
use  was,  of  course,  limited,  as  practically  the  only  grinding 
done  in  the  early  manufacturing  days  consisted  of  tool 
sharpening.  Grindstones  are  used  at  present  in  large  quan- 
tities for  sharpening  edge  tools,  cutlery,  etc.,  often  in 
preference  to  modern  abrasive  wheels.  Many  reasons  for 
this  practice  are  explained  later,  under  the  heading,  Grind- 
stones Vs.  Grinding  Wheels. 

EMERY 

Emery,  which  in  reality  is  an  impure  form  of  corundum, 
has  been  known  as  an  abrasive  from  very  remote  times.     Its 
value  as  an  abrasive  was  known  to  the  ancient  Greeks/ 
Dioscorides  referred  to  it  as  a  stone  used  in  gem  engraving. 
Emery  was  also  known  to  the  Romans,  Pliny  and  other 


EMERY 

writers  referring  to  it  as  naxium.  There  is  also  seme 
authority  for  the  statement  that  in  the  "adamant"  of 
the  Old  Testament,  translated  from  the  Hebrew,  shamir 
referred  to  emery  ore.  ^The  principal  emery  deposits  that 
furnish  the  emery  of  commerce  are  located  in  Asia  Minor, 
in  the  basins  of  the  Sarabat  and  Mender  rivers.  In  the 
Grecian  Archipelago,  the  best  known  of  these  deposits  are 
located  on  the  Island  of  Naxos,  and  in  this  country  near 
Chester,  Mass.,  and  Peekskill,  N.  Y. 

Emery  looks  like  iron  ore,  being  of  a  dense,  granular  con- 
struction. Its  luster  is  metallic,  while  its  color  runs  from 
blue-black  to  black.  It  can  truly  be  called  a  unique  mineral, 
as  it  is  a  mixture  of  alumina  oxide  and  iron  as  magnetite 
and  hematite.  At  one  time,  all  of  the  world's  supply  of 
emery  came  from  the  Grecian  Isles,  principally  Naxos,  but 
during  the  year  1847  Dr.  J.  Lawrence  Smith  located  im- 
portant emery  deposits  in  Asia  Minor.  Dr.  Smith's  dis- 
coveries proved  to  be  of  great  benefit  to  the  emery-consum- 
ing trade  owing  to  the  fact  that  the  price  of  emery  was 
materially  reduced.  Asia  Minor  or  Turkish  emery,  as  the 
new  material  was  called,  at  once  became  popular,  as  it 
proved  to  be  an  efficient  abrasive  for  many  purposes. 

Turkish  emery  always  occurs  in  limestone  or  marble, 
the  deposits  resting  on  gneiss,  schist  and  mica  slates,  while 
Naxos  emery  is  generally  found  in  limestone  beds,  being 
associated  with  crystalline  schists.  One  noticeable  dif- 
ference between  the  emery  of  the  Grecian  Archipelago  and 
that  of  Asia  Minor  is  that  in  the  former  are  numerous  small 
particles  of  mica  which  are  seldom  observed  in  the  latter «*- 

The  mining  of  both  Turkish  and  Naxos  emery  is  generally 
carried  on  in  a  very  primitive  manner.  Being  near  the  sur- 
face, the  ore  is  easily  removed  as  it  is  often  present  in  loose 
boulders.  Masses  that  are  too  large  for  transportation  to 
the  sea  coast,  are  generally  broken  into  fragments  through 
the  process  of  heating  them  for  a  number  of  hours  followed 
by  a  sudden  cooling  with  water.  This  causes  the  ore  to 
fracture  in  many  places,  and,  by  means  of  hammer  blows,  ^ 

15 


ABRASIVES  AND  ABRASIVE   WHEELS 

it  is  an  easy  matter  to  reduce  the  ore  to  pieces  suitable  for 
transportation.  The  low  cost  of  mining,  together  with 
moderate  transportation  costs,  accounts  for  the  fact  that 
Turkish  emery  finds  a  ready  sale  in  this  country  in  competi- 
tion with  American  emery.  For  the  purpose  of  grinding- 
wheel  manufacture,  however,  *&axos  emery  is  considered 
superior  to  all  other  kinds  as  it  is  the  hardest,  toughest 
and  most  uniform.  The  foregoing  sounds  like  a  broad 
statement,  to  be  sure,  but  it  is  the  consensus  of  opinion 
expressed  by  leading  grinding-wheel  manufacturers  who 
make  wheels  of  emery.  L 

The  discovery  of  emery  in  this  country  dates  back  to 
about  the  year  1830,  at  which  time  a  railroad  was  being 
built  from  Boston  to  the  Hudson  River.  In  making  a  cut 
near  Chester,  Mass.,  a  deposit  of  emery  ore  was  uncovered, 
which,  at  the  time,  was  taken  for  iron  ore.  As  previously 
stated,  emery  and  iron  ore  resemble  each  other  closely. 
Blast  furnaces  were  erected  and  provision  made  for  working 
the  ore  on  a  moderately  large  scale.  At  the  first  attempt 
to  smelt  the  ore,  however,  great  difficulties  were  encountered 
in  separating  the  iron  from  the  alumina  and  the  deposits 
were  ultimately  condemned  as  too  refractory  for  practical 
purposes. 

The  mine  remained  idle  and  almost  forgotten  for  a  num- 
ber of  years.  In  1864  or  thereabout,  Dr.  H.  S.  Lucas, 
realizing  the  possibilities  of  working  the  deposits  as  a  source 
of  abrasive  supply  to  compete  with  the  foreign  product, 
bought  the  property  and  began  to  successfully  operate  it 
as  an  emery  mine.  Operations  have  been  continued  in 
this  district  until  the  present  day.  The  emery  in  question 
is  associated  with  amphibolite  and  serpentine,  and,  as  the 
veins  of  ore  reach  several  hundred  feet  underground,  it  is 
necessary  to  work  them  by  extensive  tunneling. 

Mention  should  also  be  made  of  the  emery  deposits  in 
New  York  state  in  the  vicinity  of  Peekskill.  rhis  emery, 
which  is  called  a  spinel  emery,  does  not  occur  in  a  continu- 
ous vein,  but  in  segregated  masses,  being  associated  with 

16 


EMERY 

morite  rocks.  In  this  ore  spinel,  which  is  magnesium 
aluminate,  MgAl2o4,  furnishes  the  abrasive  agent,  since 
spinel  has  a  relative  hardness  of  8,  as  against  9,  the  hardness 
of  alumina,  it  is  seen  that  spinel  emery  is  somewhat  softer 
than  other  varieties  of  true  emery.  The  value  of  spinel 
emery  should  not  be  overlooked,  however,  as  it  furnishes 
an  efficient  polishing  material  in  cases  where  a  very  hard 
and  tough  abrasive  is  not  desired. 

The  specific  gravity  of  emery  varies  in  different  speci- 
mens from  3.7  to  4.3  and  the  percentage  of  alumina  oxide 
from  30  to  70.  The  abrasive  power,  sometimes  called  the 
effective  hardness,  is  not  proportional  to  the  amount  of 
alumina  contained,  being  influenced  to  a  great  extent  by 
the  proportions  of  other  component  parts  in  the  form  of 
impurities  such  as  silica,  lime  magnesia,  etc.,  and  the 
structure  of  the  grain  itself.  For  the  purpose  of  grinding- 
wheel  manufacture,  the  value  of  emery  as  an  abrasive  agent 
is  determined  by  the  amount  of  alumina  oxide  present  and 
the  toughness  of  the  grain  itself.  ~^ 

In  common  with  other  natural  products,  emery  ore 
varies  in'  a  number  of  characteristics.  This  is  true  not 
only  of  specimens  from  different  mines,  but  of  the  product 
of  one  mine  as  well.  To  market  a  high-grade  emery,  it  is 
necessary  to  pay  especial  attention  to  the  selection  and 
grading  of  the  crude  ore,  to  which  end  the  use  of  the  micro- 
scope cannot  be  recommended  too  strongly,  as  by  this 
means  more  can  be  learned  of  the  quality  of  the  emery 
than  by  resorting  to  any  other  method,  aside  from  the 
actual  working  test  of  the  finished  product. 

As  emery  may  have  a  high  percentage  of  alumina  and 
at  the  same  time  the  ore  may  be  so  constituted  that,  after 
crushing,  the  grains  will  seem  to  possess  no  cutting  points. 
Such  an  emery  does  not  make  a  very  efficient  grinding 
wheel. 

Some  specimens  of  emery  crush  up  into  the  proper  kind 
of  grains,  as  far  as  cutting  points  are  concerned,  but  at  the 
same  time  nothing  but  fine  grains  are  produced.  Again 


ABRASIVES  AND  ABRASIVE  WHEELS 

it  is  sometimes  noticed  that  small  flakes  of  mica  are 
scattered  through  the  ore,  which  is  sure  to  cause  trouble 
in  the  vitrifying  process  if  the  emery  is  used  in  the 
manufacture  of  vitrified  grinding  wheels.  It  is  readily 
seen  that  an  efficient  abrasive  cannot  be  made  of  an 
emery  ore  selected  at  random.  It  is  of  the  utmost  im- 
portance to  know  the  nature  of  the  grain  to  adapt  the 
same  for  a  given  abrasive  purpose. 

At  one  time,  all  grinding  wheels  were  made  of  emery. 
Of  late  years,  however,  corundum  and  the  different  artificial 
abrasives  are  used.  At  the  same  time,  notwithstanding 
the  efficiency  of  modern  abrasives,  the  more  ancient  emery 
wheel  still  has  its  field  of  usefulness,  and,  strange  as  it  may 
seem,  on  some  classes  of  grinding,  steel  castings  and  heavy 
malleables,  for  instance,  emery  wheels  continue  to  show 
the  highest  efficiency.  This  statement  is  not  made  thought- 
lessly, but  is  the  result  of  several  years  of  observation  spent 
in  representing  grinding-wheel  manufacturers. 

From  a  theoretical  point  of  view,  it  would  seem  that 
abrasives  containing  a  higher  percentage  of  alumina  than 
is  present  in  emery,  would  prove  more  efficient,  regardless 
of  the  nature  of  the  work.  Actual  tests,  however,  have 
proven  beyond  a  doubt  that  for  certain  purposes  the  emery 
wheel  is  still  in  a  position  to  successfully  compete  with 
artificial  abrasives.  This  is  explained  in  a  subsequent 
chapter. 

Again,  emery  wheels  are  comparatively  low  in  price,  and 
they  find  a  ready  market  among  consumers  whose  grinding- 
wheel  wants  are  few.  A  manufacturer  who  uses  grinding 
wheels  intermittently,  a  few  minutes  at  a  time,  is  not  con- 
cerned whether  or  not  the  wheel  shows  the  highest  efficiency. 
As  long  as  it  gives  satisfaction,  within  certain  limits,  no 
good  reason  is  see'n  why  a  higher  price  should  be  paid  for 
a  more  improved  abrasive. 

Another  factor,  that  should  be  mentioned  while  consid- 
ering the  emery  wheel,  is  that  owing  to  the  high  percentage 
of  oxide  of  iron  contained,  this  abrasive,  grit  for  grit,  leaves 

18 


EMERY 

a  finer  finish  than  any  other  abrasive  material  used  in 
grinding-wheel  manufacture.  Even  on  precision  work,  such 
as  gauge  grinding  and  other  similar  operations,  the  emery 
wheel  still  plays  an  important  part  and  it  is  often  the  choice 
of  many  engineers  who  know  abrasives  for  their  actual 
worth. 

Emery  wheels,  or  emery  stones,  as  they  are  termed  in  this 
case,  are  also  largely  used  for  hulling  oats  and  rice,  taking 
the  place  of  the  bed  and  runner  natural  stones  as  used  in  the 
ordinary  buhr  mill.  To  whom  the  credit  belongs  for  intro- 
ducing the  above  stones,  is  not  known  for  a  certainty,  but 
experience  has  proven  that  the  emery  stone  compares 
favorably  with  the  natural  stones  heretofore  used  for  this 
purpose. 

Coarse  emery  is  used  in  the  form  of  bricks  for  rubbing 
stone  and  various  metals  while  the  finer  grades  of  emery 
are  made  into  sharpening  stones,  scythe  stones,  etc.  Of 
late  years,  however,  artificial  sharpening  stones  made  of 
electro-thermic  abrasives  (Carborundum,  for  example)  have 
largely  replaced  those  made  of  emery.  For  a  few  specific 
purposes,  emery  stones  are  still  in  use  owing  to  the  high 
finish  they  produce. 

vln  the  form  of  grains  and  powders,  emery  is  used  for  a 
number  of  purposes  such  as  finishing  bevels  on  plate  glass, 
lapping  hardened  steel,  polishing  precious  stones,  etc.,  or, 
in  fact,  for  any  purpose  where  a  tough,  durable  abrasive  in 
grain  form  is  desired. 

Emery  grain  is  also  used  to  a  great  extent  on  polishing, 
or  set-up  wheels,  as  they  are  termed,  for  finishing  an  end- 
less variety  of  metal  parts  such  as  edge  tools,  cutlery,  parts 
of  firearms,  etc.  Various  kinds  of  emery  act  differently 
on  a  polishing  wheel  and  suitable  grades  for  specific  pur- 
poses are  generally  chosen  after  careful  experiment.  One 
reason  why  emery  gives  such  good  results  on  polishing 
wheels  is  that  its  comparatively  rough  fracture  presents 
a  good  holding  surface  for  the  glue,  which  factor  is  not 
true  of  many  of  the  manufactured  abrasives.  Carborun- 

19 


ABRASIVES  AND  ABRASIVE  WHEELS 

dum,  on  account  of  its  smooth,  glassy  surface,  does  not 
form  a  very  efficient  abrasive  to  use  on  a  polishing  wheel. 

Emery  paper  and  cloth  are  used  to  a  large  extent  in  the 
mechanical  arts  for  smoothing  and  polishing  small,  intricate 
parts  of  small  machinery  and  instruments. 

In  the  study  of  the  occurrence  of  emery,  we  are  con- 
fronted with  two  very  curious  facts.  First,  emery  is  a 
mixture  of  iron  oxides  and  alumina  and,  second,  this  com- 
position occurs  in  but  few  places  in  the  world — pin  points 
on  the  earth's  surface,  as  it  were.  In  American  emery,  Prof. 
J.  H.  Pratt  regards  the  alumina  and  iron  oxides  as  basic 
segregations  from  an  igneous  magma.  This,  of  course,  is 
within  reason  since  it  is  an  accepted  fact  that  the  earth 
was  at  one  time  a  molten  mass  of  elements,  and  as  this 
mass  slowly  cooled,  the  various  elements  combined  and 
sometimes  segregated.  What  force  of  nature  caused  the 
elements  of  iron  and  alumina  to  segregate  together,  in 
practically  the  same  manner,  is  beyond  the  knowledge  of 
the  writer. 

CORUNDUM 

V 

The  name  corundum  was  originally  applied  to  the  ruby 
and  sapphire  of  India,  the  word  being  derived  from  the 
Sanskrit  (kurminda)  and  literally  means  ruby.  The  variety 
of  corundum  we  are  dealing  with  is  called,  by  the  older 
mineralogists,  impure  corundum  and  comprises  the  numerous 
varieties  that  are  not  transparent  or  perfect  enough  to  be 
used  as  gem  stones. 

Some  thirty  years  ago,  corundum  was  regarded  as  a 
comparatively  rare  mineral,  but  at  the  present  time  it  is 
known  to  occur  abundantly  in  several  localities  in  this 
country  and  in  Ontario,  Canada.  In  this  country,  it  occurs 
in  igneous  rocks,  principally  syenites,  and  in  several  gneisses 
and  schists.  It  also  occurs  in  alluvium  deposits  in  sands  and 
gravels.  Canadian  corundum  occurs  in  nepheline  syenite 
associated  with  Laurentian  gneiss. 

Of  the  origin  of  corundum  but  little  is  known  for  a  cer- 


CORUNDUM 

tainty,  as  a  study  of  his  mineral  calls  for  exhaustive  research 
work  on  the  part  of  the  geologist,  who  is  sometimes  reticent 
when  it  conies  to  establishing  hard  and  fast  rules.  Prof. 
J.  H.  Pratt,  who  has  made  a  deep  study  of  the  occurrence 
of  corundum,  in  this  country  and  elsewhere,  considers  that 
the  corundum  of  North  Carolina  segregated  from  a  molten 
magma,  the  separation  taking  place  at  an  early  period  of 
consolidation.  ^ 

Canadian  corundum  has  of  recent  years  been  regarded 
as  an  essential  rock  constituent.  Regarding  the  corundum 
of  Ontario,  H.  E.  T.  Haultain  states  that  the  corundum- 
bearing  rocks  are  not  dykes,  that  they  are  not  eruptive, 
and  that  there  is  no  sign  of  separation  from  magma. 

The  principal  Canadian  deposit  of  corundum  occurs  at 
Craig  Mountain,  which  is  situated  in  Raglan  Township, 
Renfrew  County,  Ontario.  In  this  country,  corundum  is 
found  in  the  following  states:  Maine,  Massachusetts, 
Connecticut,  New  York,  Pennsylvania,  Delaware,  Virginia, 
North  Carolina,  South  Carolina,  Tennessee,  Georgia,  Col- 
orado, Montana,  California  and  Idaho. 
'"'  Corundum  is  found  in  three  different  ways;  block  corun- 
dum, crystal  corundum  and  sand  corundum.  Under  the 
heading  of  block  corundum,  is  included  corundum  found  in 
masses  whether  large  or  small.  (  This  is  the  most  difficult 
form  of  corundum  to  mine.  Owing  to  its  extreme  hardness, 
it  is  impossible  to  drill  it  for  the  purpose  of  blasting.  Thus 
it  is  not  easily  broken  up.  When  block  corundum  is  mixed 
with  foreign  substances,  such  as  feldspar,  hornblende,  etc., 
it  is  often  difficult  to  clean,  whereas  a  block  corundum 
free  from  superfluous  foreign  matter  makes  an  ideal  ore, 
provided  the  parting  planes  are  -not  too  well  developed. 
The  disadvantage  of  numerous  parting  planes  is  explained 
later. 

Corundum  crystallizes  in  the  rhombohedral  division  of 
the  hexagonal  system  and  under  the  head  of  crystal  corun- 
dum is  included  all  the  crystal  varieties  of  corundum 
which  occur  in  block  corundum  or%in  sand  or  gravel. 

21 


ABRASIVES  AND  ABRASIVE  WHEELS 

Some  of  these  crystals  take  the  form  of  a  hexagon  with  a 
prism  at  each  end,  in  which  case  the  crystal  is  termed 
"barrel  corundum."  Many  of  these  crystals  are  of  no  defi- 
nite form,  being  enclosed  in  compact  masses  of  surrounding 
material. 

Very  small  crystals  and  small  grains  are  termed  sand 
corundum  and  often  occur  between  a  corundum-bearing 
peridotite  rock  and  the  surrounding  gneiss  or  schist. 

Corundum  possesses  no  true  cleavage,  but  parting  planes 
are  usually  present  along  which  the  crystal  fractures.  How- 
ever, if  these  planes  are  so  numerous  as  to  be  present  in 
the  small  grains  of  abrasive  material  that  constitute  a 
grinding  wheel,  a  low  abrasive  efficiency  will  be  the  result 
because  the  grains  will  readily  fracture,  thus  breaking  away 
before  becoming  dull  and  useless. 

An  ideal  corundum  for  an  abrasive  wheel  is  one  wherein 
the  grains  are  free  from  parting  lines,  thus  they  will,  on 
becoming  dull,  break  with  the  irregular  to  conchoidal  frac- 
ture, which  is  a  characteristic  of  corundum.  As  a  matter 
of  fact,  all  varieties  of  corundum  have  comparatively  the 
same  degree  of  hardness,  that  is,  from  8.8  to  9.,  but  some 
varieties  are  much  higher  in  abrasive  efficiency  than  others. 
This  is  due  to  the  fact  that  the  parting  planes  are  sometimes 
too  numerous  as  previously  stated.  This  accounts  for  the 
fact  that  some  makes  of  corundum  wheels  are  superior  to 
others.  The  only  practical  test  for  the  abrasive  efficiency 
of  a  doubtful  corundum  is  to  make  some  sample  wheels  of 
it  and  have  them  tested  on  actual  work  under  every-day 
working  conditions. 

From  a  theoretical  point  of  view,  corundum  contains 
but  two  elements,  alumina  and  oxygen,  its  chemical  formula 
being  A12O3.  Commercial  corundum,  as  well  as  the  gem 
varieties,  generally  contains  a  trace  of  silica,  ferric  oxide 
and  combined  water.  The  following  table,  which  is  taken 
from  Bulletin  No.  269  of  the  United  States  Geological 
Survey,  gives  the  chemical  analyses  of  several  well-known 
corundums. 


CORUNDUM 


ANALYSES  OF   CORUNDUM 


Locality 

A1.0, 

Per 
Cent. 

Fe2O3 
Per 
Cent. 

SiO2 
Per 
Cent. 

(H,0) 
Per 

Cent. 

Insoluble 
residue 
Per 
Cent. 

Total 

Analyst 

Hastings  County, 
Ontario  
Sapphire  from  India 
Ruby  from  India  .  .  . 
Corundum  Hill  M  ine  , 
N.  Carolina  
Laurel  Creek  Mine, 
Georgia  

96.92 
97-Si 
97-32 

98.79 
95-51 

'i'89 
1.09 

-75 
.88 

0.80 

I.  21 
.90 

i-45 

2.43 

.78 
•74 

1-36 

100.  71 

IOO.  2C 
99.62 

100.22 

98.58 

Wells 
Smith 
Smith 

Emerson 
Emerson 





Since  corundum  occurs  more  abundantly  than  emery,  the 
consumer  of  grinding  wheels  often  asks  why  corundum 
wheels  command  a  higher  price  than  wheels  made  of  emery. 
It  is  true  that  corundum  deposits  are  numerous,  but  not 
all  of  these  corundums  are  of  the  correct  structure  for 
grinding-wheel  use,  as  above  explained,  and,  again,  co- 
rundum goes  through  a  comparatively  expensive  process 
before  it  is  fit  for  the  grinding-wheel  manufacturers. 

It  must  be  borne  in  mind  that  corundum,  as  it  comes  from 
the  mine,  is  not  in  a  pure  state,  being  mixed  with  other 
minerals,  such  as  feldspar,  hornblende,  margartite,  mus- 
covite,  etc.  Corundum  is  sometimes  found  in  huge  masses 
weighing  many  tons  and  in  cases  of  this  kind,  the  elimi- 
nation of  the  foreign  matter  is  often  a  difficult  problem. 
Again,  a  corundum  that  is  to  be  used  in  the  manufacture 
of  vitrified  wheels  should  be  free  from  such  substances  as 
mica,  garnet  and  feldspar.  Otherwise  difficulties  are  sure 
to  be  encountered  in  the  vitrifying  process. 

In  describing  the  methods  used  in  mining  and  cleaning 
corundum  for  the  market,  it  may  be  well  to  first  consider 
the  mines  at  Craigmont,  Canada,  as  the  methods  and  facili- 
ties used  there  are  generally  acknowledged  to  be  the  most 
up-to-date  and  practicable. 

The  above  mine  is  worked  by  the  Manufacturers  Co- 
23 


ABRASIVES  AND  ABRASIVE  WHEELS 

rundum  Company,  Limited,  and  the  following  account  of 
the  cleaning  methods,  etc.,  is  taken  from  an  article:  "Co- 
rundum at  Craigmont,"  which  appeared  in  the  Canadian 
Mining  Journal  under  the  date  of  August  ist,  1907.  As 
this  article  was  written  by  Mr.  H.  E.  T.  Haultain,  who  was 
general  manager  of  the  company  at  the  time,  it  is  interest- 
ing as  well  as  authentic. 

"The  first  discovery  of  corundum  in  Ontario  was  made 
nearly  thirty  years  ago  on  this  Craig  Mountain,  then  known 
as  Robillard's  Hill,  by  Henry  Robillard's  daughter.  As  a 
small  child,  she  picked  up  and  carried  home  a  crystal  that 
'looked  like  a  cruet  stopper.'  For  years  it  remained  as 
an  unnamed  curiosity,  but  at  the  time  of  the  phosphate 
excitement,  it  was  declared  to  be  phosphate,  and  Robillard 
and  Fitzgerald  located  the  ground  as  a  phosphate  mine. 

"In  1896,  Ferrier,  of  the  Geological  Survey,  described  the 
presence  of  corundum  in  the  neighboring  township.  Mining 
operations  were  commenced  in  May,  1900,  the  ore  being 
transported  in  wagons  half  a  mile  to  a  small  mill  driven  by 
water  power.  In  March,  1904,  the  present  mill  commenced 
crushing.  This  mill  is  by  far  the  largest  corundum  mill 
ever  built,  and  is  the  largest  concentrating  plant  in  Canada. 
It  has  three  divisions,  the  main  mill,  the  grader,  and  the 
finishing  department.  The  latter  is  a  comparatively  recent 
development. 

"  In  the  main  mill,  the  rock  is  crushed  on  till  90  per  cent. 
of  it  will  pass  through  a  2.5  millimeter  hole,  by  means  of 
four  rock  breakers  and  five  sets  of  rolls.  It  is  concentrated 
on  20  Overstrom  tables;  the  concentrates,  which  contain 
from  50  to  60  per  cent,  corundum,  passing  into  bins  for 
drainage. 

"In  the  grader,  these  concentrates  are  dried,  passed  over 
magnetic  separators,  separated  into  20  sizes,  from  8  mesh 
to  200  mesh,  and  still  further  subjected  to  concentration 
on  Wilfley  tables  and  Hooper  pneumatic  jigs.  The  result- 
ing product  is  again  dried  and  again  sized  and  passed  into 
bins,  from  which  it  is  drawn  off  into  zoo-pound  bags.  The 

24 


CORUNDUM 

run  of  bags  each  day  is  sampled  by  hand,  every  size  by 
itself,  and  these  samples  are  carefully  assayed,  and  accord- 
ing to  the  assay  results,  the  bags  are  stocked  in  the  finishing 
department. 

"The  finishing  department  performs  three  functions.  It 
thoroughly  mixes  the  product  so  as  to  give  a  uniform  ma- 
terial complying  closely  with  fixed  standards.  It  re-screens 
each  size  so  as  to  eliminate  the  results  of  carelessness  in 
the  grader.  It  automatically  samples  every  lot  of  thirty 
bags. 

"The  finishing  foreman,  knowing  the  assays  of  the  con- 
tents of  his  bags,  mixes  thirty  hundredweight  at  a  time 
in  a  hopper.  From  this  hopper,  the  corundum  passes  in  a 
thin,  flat  stream  past  a  draft  of  air,  which  blows  away  the 
mica.  It  then  passes  over  a  set  of  shaking  screens,  which 
screen  out  both  undersize  and  oversize  particles  and  from 
this  it  passes  to  a  bin  whence  it  is  drawn  off  past  an  auto- 
matic sampler  direct  into  canvas  bags,  which  are  filled  to 
contain  100  pounds  of  corundum. 

"The  bags  are  then  sewn  up  by  machinery  and  marked 
for  size  and  lot  number.  The  samples  are  tested  by  hand 
screens  for  accuracy  of  sizing,  by  the  eye  for  pyrites  and 
hornblende  contents,  by  the  magnet  for  magnetite  contents, 
and  in  the  assay  office  for  both  corundum  and  iron  content. 

"On  receipt  of  the  assay  results,  the  bags  are  marked  G 
or  Gi,  G  grade  being  for  silicate  wheels  and  the  polishing 
trade,  and  Gi  for  the  vitrified  wheel  trade.  A  sample 
weighing  about  half  a  pound,  representing  each  lot  of 
thirty  bags,  is  stored  for  reference." 

As  before  stated,  corundum  is  found  in  many  parts  of 
this  country;  one  of  the  well-known  mines  is  called  the 
Corundum  Hill  Mine.  It  is  located  in  Macon  County, 
North  Carolina.  Corundum  was  discovered  here  in  1870 
and  mining  operations  were  commenced  a  year  later.  This 
corundum  is  found  in  a  peridotite  rock.  The  above  mine 
yields  block,  crystal  and  sand  corundum  having  a  high 
abrasive  efficiency  in  both  silicate  and  vitrified  wheels. 

25 


ABRASIVES  AND  ABRASIVE  WHEELS 

The  corundum  of  this  mine  enjoys  a  wide  reputation,  in- 
deed, one  well-known  manufacturer  of  grinding  wheels  ad- 
vertises the  fact  that  this  brand  of  corundum  is  used. 

Another  famous  mine,  the  Laurel  Creek  mine,  is  located 
in  Rabun  County,  Georgia.  This  corundum  is  also  found  in 
peridotite  and  often  in  massive  blocks,  many  of  them  weigh- 
ing several  hundred  pounds.  One  mass  of  corundum  taken 
from  this  mine  is  reported  to  have  weighed  over  5,000 
pounds.  It  is  said  that  this  mine  has  furnished  the  largest 
masses  of  corundum  ever  mined  in  any  locality. 

An  excellent  grade  of  corundum  is  also  found  in  Gallatin 
County,  Montana,  where  it  occurs  in  a  syenite  rock.  The 
crystals  are  of  all  sizes  up  to  eight  inches  long  and  some 
have  been  found  that  weighed  two  pounds.  Montana 
corundum  is  being  worked  by  modern  methods.  The 
mills  are  equipped  with  up-to-date  machinery.  Several 
grinding-wheel  manufacturers  have  used  this  corundum, 
reporting  it  as  making  an  excellent  grinding-wheel  grade. 

The  above  corundum  deposits  are  mentioned  because 
they  are  well  known  to  the  corundum-consuming  trade. 
It  must  not  be  inferred  from  this,  however,  that  excellent 
grades  of  corundum  are  not  found  elsewhere  in  this  country. 
As  a  matter  of  fact,  there  are  over  160  corundum  deposits 
that  have  been  listed  by  geologists,  many  of  them  yielding 
an  excellent  grade  of  material. 

Abrasive  engineers  admit  that  corundum  of  the  right  kind 
makes  a  very  efficient  grinding  wheel  for  all  purposes,  with 
the  exception  of  materials  of  low  tensile  strength  such  as 
cast  iron,  etc.,  and  since  corundum  occurs  so  plentifully, 
the  question  is  often  asked:  why  is  it  not  used  more  ex- 
tensively? This  is  at  best  a  difficult  question  to  answer, 
but  we  may  throw  some  light  on  the  subject  by  considering 
some  facts  that  exist  concerning  the  corundum  industry. 

To  begin  with,  the  older  methods  of  preparing  the  abrasive 
for  the  market  were  unsatisfactory;  this  resulting  in  an 
imperfectly  cleaned  grain  not  wholly  free  from  impurities, 
for  it  is  only  within  the. last  few  years,  comparatively  speak- 

26 


CORUNDUM 

ing,  that  modern  appliances,  such  as  used  at  the  Canadian 
mines,  have  been  installed  in  this  country. 

In  the  old  process  of  cleaning,  the  ore  was  crushed  in  rock 
crushers  and  then  re-crushed  by  passing  it  between  a  series 
of  rolls.  The  resulting  grain  was  then  washed  in  running 
water,  the  corundum,  being  the  heaviest,  settled  while  the 
lighter  impurities  were  carried  away.  This,  of  course, 
applied  only  to  such  substances  as  were  not  attached  to 
the  grains  of  corundum  themselves.  The  material  was  then 
"scoured"  by  passing  it  through  a  machine  not  unlike  a 
screw  conveyor  and  afterward  re- washed.  The  grain  then 
received  a  further  cleaning  in  a  wet  pan  muller,  which 
consists  of  a  revolving  pan  having  a  shaft  over  it  carrying 
two  wooden  rollers.  The  action  of  the  muller  caused  the 
grains  to  rub  against  each  other,  thus  gradually  wearing 
away  the  impurities  which  were  carried  away  by  a  stream 
of  running  water.  The  material  was  then  thoroughly  dried 
and  sieved  to  the  various  commercial  sizes. 

The  old  process  was  expensive  and  uncertain  as  to  re- 
sults. Again,  severe  competition  with  artificial  abrasives 
began  to  creep  in.  The  Carborundum  Company  was  spend- 
ing large  sums  of  money  int'oducing  their  product  to  the 
manufacturing  world  and  the  Norton  Company  was  not 
far  behind  in  extolling  the  merits  of  their  artificial  corundum 
called  Alundum.  That  it  pays  to  advertise  is  an  old  and 
true  saying  and  artificial  abrasives  certainly  have  had  the 
advantage  of  wide  publicity.  Again,  the  artificial  abrasives 
were  uniform,  whereas  corundum,  when  taken  as  a  whole, 
was  not,  since  it  was  the  product  of  many  deposits,  which 
naturally  varied  to  some  extent. 

It  is  the  writer's  opinion,  given  for  what  it  is  worth,  that 
corundum  as  an  abrasive  has  been  handled  wrong  from  the 
start.  It  has  always  been  sold  as  a  raw  material,  in  com- 
petition with  emery  at  first  and  later  in  competition  with 
the  artificial  abrasives.  The  miners  of  corundum,  even  of 
the  very  best  qualities,  were  more  than  willing  to  sell  their 
product  to  all  who  wished  to  purchase,  regardless  of  the 

•27 


ABRASIVES  AND  ABRASIVE  WHEELS 

fact  that  not  all  manufacturers,  a  few  years  ago,  knew  how 
to  make  the  best  quality  of  grinding  wheels. 

The  writer  fully  realizes  that  it  is  a  simple  matter  to  say, 
"I  told  you  so,"  but,  nevertheless  he  ventures  the  opinion 
that  if,  upon  the  discovery  of  an  exceedingly  good  quality 
of  corundum,  the  mine  owners  had  gone  into  the  wheel- 
making  business,  absolutely  controlling  the  sale  of  their 
product  and  keeping  the  same  up  to  a  high  standard,  the 
story  of  corundum  could  have  been  written  differently  at 
the  present  time. 

As  a  means  of  verifying  the  above  statement,  let  us  con- 
sider The  Carborundum  Company  for  a  moment.  Suppose 
they  had  been  willing  to  sell  their  product  to  all  wheel 
manufacturers  who  cared  to  purchase.  Would  the  carbo- 
rundum grinding  wheel  hold  the  high  position  that  it  does 
at  the  present  day?  Decidedly  not.  Carborundum  wheels 
of  all  kinds,  good  and  bad,  would  have  been  on  the  market 
and  the  result  would  have  been  that  carborundum  would 
have  lost  favor  in  a  great  many  cases. 

Now  it  is  a  far  easier  matter  to  make  a  poor  grinding 
wheel  than  it  is  to  produce  a  good  one  and  here  we  have 
the  answer  regarding  corundum,  an  abrasive  occurring 
abundantly  and  possessing  the  highest  abrasive  qualities, 
which  now  occupies  an  inferior  position  simply  because 
"too  many  cooks  spoiled  the  broth."  Everybody  had 
corundum  wheels  for  sale — wheels  made  of  pure  corundum 
— certainly.  At  the  same  time,  however,  some  of  this 
"pure"  corundum  was  unfit  for  wheel  manufacture,  while 
in  other  cases  corundum  of  the  highest  grade  was  given  a 
bad  name  because  the  actual  value  of  the  abrasive  was 
hidden  in  a  poorly  made  grinding  wheel. 

How,  then,  should  corundum  have  been  handled?  some 
one  is  sure  to  ask.  The  answer  is  simple.  As  before  stated, 
the  owners  of  a  good  corundum  deposit  should  have  en- 
gaged in  the  wheel-making  end  of  the  business,  given  their 
brand  of  corundum  a  good  name,  spent  a  hundred  thousand 
dollars  in  equipment,  and  several  hundred  thousand  more 

28 


DIAMOND 

in  advertising  their  product,  and  the  business  would  have 
developed  itself.  The  sole  ownership  of  a  widely  advertised 
product  is  a  gold  mine  in  itself  provided,  of  course,  the 
business  is  properly  handled,  and  this  is  one  factor  that 
has  made  manufactured  abrasives  r»««th  distinctive  names 
so  universally  used. 

Corundum  is  used  for  a  number  of  purposes,  and,  in 
comparing  it  with  emery,  it  is  a  faster  cutting  abrasive 
owing  to  its  pure  state.  Corundum  wheels  are  used  prin- 
cipally for  steel  grinding  on  both 'rough  and  precision  work, 
while  corundum  in  grain  and  powder  form  is  used  for  vari- 
ous grinding  and  polishing  operations.  Sharpening  stones 
made  of  corundum  are  very  efficient,  while  corundum- 
coated  paper  and  cloth  are  also  put  to  a  number  of  uses, 
principally  in  the  form  of  discs  used  on  the  disc-type  of 
grinder  for  finishing  steel  parts,  both  hard  and  soft.  Taken 
as  a  whole,  corundum  covers  a  wide  field  and  by  many  it 
is  considered  to  be  the  best  all-round  abrasive  known. 

DIAMOND 

Diamonds  are  divided  into  three  groups,  the  transparent 
and  practically  flawless  varieties  used  as  gem  stones  and  im- 
perfect stones  called  bort  diamonds.  There  is  also  a  black 
diamond  often  called  carbonado.  The  diamond  has  a  specific 
gravity  of  3.50  and  is  the  hardest  substance  known,  being 
placed  at  10  on  the  mineralogist's  scale.  The  diamond 
crystallizes  in  the  cubic  system,  generally  taking  the  form 
of  an  octahedron. 

The  fracture  of  the  diamond  is  conchoidal  and  the  crystals 
invariably  •  cleave  along  planes  parallel  to  the  octahedral 
faces.  Diamond  cutters  avail  themselves  of  this  character- 
istic when  reducing  the  stone  to  the  best  shape  for  cutting. 
Of  late  years,  however,  a  sawing  process  has  been  developed 
which  is  said  to  be  superior  to  the  older  method  of  cleaving 
by  means  of  a  sharp  blow. 

The  diamond  is  found  in  India,  South  America,  South 
29 


ABRASIVES  AND  ABRASIVE  WHEELS 

Africa,  New  South  Wales,  Borneo,  and  British  Guiana. 
At  the  present  time,  most  of  the  diamond  industry  centers 
in  South  Africa,  the  mines  in  this  locality  having  been 
worked  since  1870.  Previous  to  this  time,  diamonds  were 
found  in  alluvial  deposits  and  in  conglomerates,  but  in 
the  South  African  mines,  the  most  famous  of  which  are 
the  Kimberley  and  the  De  Beers  mines,  the  diamonds  are 
found  imbedded  in  a  kind  of  blue  clay  in  what  are  termed 
"pipes."  These  are  supposed  to  be  filled-up  craters  of 
long-extinct  volcanoes. 

Of  the  origin  of  the  diamond  but  little  is  known,  although 
many  eminent  geologists  have  advanced  well-grounded 
theories  concerning  its  formation,  but,  as  the  original  con- 
dition of  the  carbon,  of  which  the  diamond  is  composed, 
remains  a  question,  the  genesis  of  the  diamond  is  still  un- 
solved. 

The  De  Beers  Company  mine  many  hundred  thousand 
dollars'  worth  of  diamonds  weekly  and  it  is  needless  to  state 
that  operations  are  conducted  on  a  large  scale,  under  the 
supervision  of  the  most  able  mining  engineers  available. 
To  get  at  the  diamond-bearing  blue  clay,  a  shaft  is  sunk 
several  hundred  feet  into  the  earth  just  outside  the  pipe, 
tunnels  from  this  shaft  running  into  the  diamond-bearing 
deposits.  This  material  is  hoisted  to  the  ground  above, 
where  it  is  spread  out  in  large  fields  to  allow  the  sun  and 
rain  to  crumble  it  to  the  extent  of  being  easily  washed. 
This  weathering  process  is  materially  aided  by  going  over 
the  deposits  occasionally  with  steam-plows. 

The  disintegrated  soil  is  next  washed  in  shallow  cylin- 
drical troughs  wherein  the  diamonds  are  swept  to  the  rim 
by  means  of  revolving  toothed  arms,  the  lighter  material 
escaping  at  the  center.  The  findings  are  now  concentrated 
to  separate  the  diamonds  from  hard  foreign  substances 
and  then  a  further  separation  is  effected  by  passing  the 
concentrates  over  a  greased  surface.  For  some  unaccount- 
able reason,  the  greased  surface  holds  the  diamonds  while 
the  other  worthless  materials  escape. 

30 


DIAMOND 

It  takes,  on  an  average,  four  tons  of  blue  ground  to  yield 
one  carat  weight  of  diamond,  and  as  the  De  Beers  mines 
often  yield  from  three  to  four  pounds  of  diamonds  a  day,  it 
is  seen  that  an  immense  amount  of  blue  ground  has  to  be 
worked. 

The  next  step,  and  a  very  interesting  one,  is  to  sort  out 
the  diamonds  both  for  color  and  purity.  The  color  runs 
from  clear  white  to  black,  a  pale  yellow  being  the  most 
common  color.  The  only  difference  between  a  gem  stone 
and  a  bort  diamond  is  that  the  former  is  practically  flaw- 
less and  of  good  color,  while  the  latter  contains  black  specks 
and  other  flaws,  has  no  brilliancy  and  possesses  an  irregular 
fracture. 

It  is  needless  to  state  that  the  diamond  sorters  are  expert 
at  their  work  and  they  never  let  a  gem  stone  pass  for  a  bort. 
As  a  matter  of  fact,  dealers  in  bort  stones  look  in  vain  for 
a  gem  stone  that  might  have  missed  the  eye  of  the  inspector, 
but  there  is  no  record  of  their  efforts  being  rewarded. 

Aside  from  truing  grinding  wheels,  bort  diamonds  are 
used  for  many  other  purposes.  In  powdered  form,  they 
are  used  for  diamond  cutting,  this  process  being  introduced 
by  L.  von  Berquen  in  the  year  1476,  for  cutting  and  drilling 
very  hard  substances,  for  certain  kinds  of  delicate  lapping 
and  grinding  in  watch  factories  and  occasionally  for  very 
minute  turning  operations  in  the  watch  or  jeweler's  lathe. 

The  process  of  converting  bort  diamonds  into  diamond 
powder  is  simple,  being  carried  out  as  follows:  Several 
bort  stones  are  first  crushed  in  a  little  mortar  made  especially 
for  this  purpose  and  the  material  thus  obtained  is  placed 
in  a  quantity  of  the  very  best  olive  oil.  The  mixture  is 
thoroughly  stirred  and  allowed  to  stand  for  five  minutes. 
The  oil  is  then  poured  off  and  the  diamond  powder  that 
remains  in  the  vessel  is  called  No.  o.  The  oil  is  now  allowed 
to  stand  for  ten  minutes  and  again  poured  off,  the  remain- 
ing powder  being  known  as  No.  i.  To  get  the  various 
grades,  the  time  limits  used  are  shown  in  the  accompanying 
table. 


ABRASIVES  AND  ABRASIVE  WHEELS 

Five  minutes  ......................  No.  o 

Ten  minutes  .......................  No.  i 

Thirty  minutes  ....................  No,  2 

One  hour  ..........................  No.  3 

Two  hours  .....  ...................   No.  4 

Ten  hours  .........................  No.  5 

The  oil  is  now  allowed  to  stand  until  it  shows  clear,  the 
particles  settling  at  the  bottom  being  known  as  No.  6. 

Carbonado,  often  called  black  diamond,  is  a  form  of 
diamond  found  in  Brazil,  South  America.  It  is  of  irregular 
form  and  of  a  black,  gray  or  brown  color.  It  possesses  no 
cleavage  and  breaks  with  a  granular  fracture.  Its  specific 
gravity  is  less  than  that  of  the  true  diamond.  It  is  found 
almost  exclusively  in  the  state  of  Bahia  in  what  is  called 
cascalho,  or  diamond-bearing  gravel.  It  is  generally  found 
in  small  pieces,  although  occasionally  a  large  piece  is  dis- 
covered, the  largest  on  record  having  a  weight  of  3,150 
carats. 

For  truing  grinding  wheels,  carbonado  is  superior  to  bort 
diamond  owing  to  the  fact  that  absence  of  cleavage  makes 
the  stone  less  liable  to  fracture.  Thus  carbonado  is  the 
ideal  form  of  diamond  to  use  in  rock  drills  and  diamond 
saws  where  the  stone  must  withstand  the  impact  of  re- 
peated shocks  that  would  speedily  ruin  a  bort  stone. 

GARNET 

The  name  garnet  is  applied  to  a  group  of  very  closely 
related  minerals,  some  of  which,  in  the  pure  varieties,  are 
used  as  gem  stones.  There  are  six  kinds  of  garnet  known 
as  follows: 


Lime  alumina  garnet 

Lime  iron  garnet 

Lime  chrome  garnet  ......................  Ca3Cr2Si3Oi2 

Magnesia  alumina  garnet 
Iron  alumina  garnet 
Manganese  alumina  garnet 

Garnet   crystallizes  in   the   cubic   system,    generally   in 
rhombic  dodecahedra.     It  possesses  an  imperfect  cleavage, 

32 


GARNET 

the  parting  lines  running  parallel  to  the  dodecahedron. 
Its  hardness  varies  from  6.5  to  7.5  while  its  specific  gravity 
also  varies  to  quite  an  extent,  in  different  specimens  running 
from  3.4  to  4.3. 

Garnet  has  been  found  in  crystalline  schists,  gneiss,  gran- 
ite, metamorphic  limestone,  serpentine  and  volcanic  rocks. 
In  this  country,  deposits  are  located  in  New  York,  New 
Hampshire,  Connecticut,  Pennsylvania  and  North  Caro- 
lina. Large  quantities  of  garnet  are  mined  in  New  York 
state,  the  deposits  being  located  in  the  vicinity  of  the 
Adirondack  Mountains.  This  garnet,  which  occurs  in 
limestone  and  gneiss,  is  of  the  iron-alumina  variety.  It  is 
often  called  Almandine.  The  garnet  of  New  Hampshire  is 
also  of  the  above  variety  while  North  Carolina  garnet  occurs 
in  two  forms,  the  iron-alumina  and  a  subdivision  called 
rhodolite,  which  consists  of  two  parts  magnesia  alumina  and 
one  of  iron-alumina  garnet. 

An  excellent  garnet,  known  to  the  trade  as  Spanish 
mineral,  is  mined  in  Spain.  This  material  is  extensively 
used  in  this  country;  in  fact,  one  large  manufacturer  of 
garnet  paper  uses  it  exclusively.  There  are  no  analyses  on 
record  to  establish  the  composition  of  this  material,  although 
The  United  States  Geological  Survey  informed  the  writer 
that  it  is  probably  an  iron-alumina  garnet,  or  almandine. 

Garnet  is  prepared  for  abrasive  uses  by  crushing,  concen- 
trating and  magnetic  separation  to  remove  the  superfluous 
iron  oxide,  after  which  it  is  graded  into  various  commercial 
sizes.  As  an  abrasive  for  smoothing  wood,  garnet  paper 
and  cloth  enjoys  great  popularity,  showing  high  efficiency 
over  ordinary  sandpaper,  especially  on  comparatively  hard 
woods,  such  as  oak,  cherry,  maple,  etc.  It  is  not  a  suitable 
abrasive  for  grinding-wheel  manufacture,  owing  to  its  soft 
nature,  although  it  is  sometimes  mixed  with  corundum 
in  the  manufacture  of  silicate  wheels  for  such  operations  as 
knife  grinding. 

The  pure  varieties  of  garnet  are  often  cut  as  gem  stones  of 
which  there  are  many  colors  from  deep  red  to  light  rose. 

33 


ABRASIVES  AND  ABRASIVE  WHEELS 

Some  of  the  finest  garnet  gem  stones  are  found  in  loose 
gravel  in  Macon  County,  N.  C. 


QUARTZ 

Quartz  is  one  of  the  most  common  of  minerals  and  has 
a  wide  distribution  throughout  the  world.  It  is  composed 
of  silicon  dioxide,  or  silica  SiO2.  Aside  from  being  an 
essential  constituent  of  some  igneous  rocks,  as  granite,  it 
occurs  as  sand  and  in  crystals.  Its  specific  gravity  is 
2.65  while  its  hardness  is  placed  at  7  on  Moh's  scale.  It 
crystallizes  in  the  trapezohedral-hemihedral  class  of  the 
rhombohedral  division  of  the  hexagonal  system.  In  its  pure 
state,  it  forms  many  semi-precious  stones  such  as  the 
amethyst,  bloodstone,  sardonyx  and  others.  It  has  no 
true  cleavage  and  breaks  with  a  conchoidal  fracture. 

As  an  abrasive,  quartz  has  many  uses.  In  grain  form, 
large  quantities  of  it  are  used  for  plate-glass  grinding  and 
in  other  forms  of  glass  work.  Glued  on  belts,  it  is  used 
for  sanding  implement  and  tool  handles.  Owing  to  its 
hardness  and  sharpness,  it  is  often  used  for  sand  blasting. 
For  sawing  stone  of  the  softer  varieties,  such  as  marble  and 
limestone,  quartz  forms  a  cheap  and  efficient  medium.  It 
is  not  adapted  to  grinding- wheel  manufacture  although 
it  is  sometimes  mixed  with  other  abrasives  in  making  knife- 
grinding  wheels. 

FLINT 

Flint  is  a  very  hard,  brown-colored  stone  being  composed 
principally  of  silica  and  having  a  specific  gravity  of  2.6. 
Its  fracture  is  conchoidal.  It  is  one  of  the  oldest  known 
minerals,  being  used  by  prehistoric  man  in  the  manufacture 
of  implements  and  weapons.  It  was  once  widely  used  for 
striking  fire  and  until  the  invention  of  the  percussion  cap 
the  flint-lock  musket  was  used  the  world  over.  Thus  it  is 
seen  that  this  now  little  used  material  once  played  an 
important  part  in  shaping  the  destinies  of  nations.  A 

34 


NATURAL  SHARPENING  STONES 

form  of  flint  called  flint-quartz  is  used  in  making  the  flint 
paper  of  commerce  which  is  more  commonly  spoken  of  as 
sand-paper.  In  this  country,  the  material  in  question  is 
mined  in  several  places,  the  more  important  deposits  being 
in  Maine,  Maryland  and  Wisconsin. 

NATURAL  SHARPENING  STONES 

Under  this  heading  are  included  all  the  natural  stones 
used,  as  hand  stones,  hones,  etc.,  for  various  sharpening 
operations.  Sharpening  stones  are  of  very  ancient  origin, 
specimens  having  been  unearthed  in  Egypt  dating  back  to 
1500  B.  c.  Pliny, ^writing  early  in  the  Christian  era,  tells 
of  a  stone  from  Crete  used  with  oil  and  one  from  Naxos 
used  with  water.  The  latter,  in  all  probability,  was  noth- 
ing more  or  less  than  a  fragment  of  emery  ore.  The  oldest 
natural  stone  of  modern  civilization  is  the  Turkey  stone 
mined  in  Asia  Minor.  This  stone  became  popular  over 
one  hundred  years -ago  and  to  some  extent  is  used  at  the 
present  day.  Other  famous  sharpening  stones  of  a  century 
ago  were  the  Belgian  razor  hone,  which  owes  its  abrasive 
qualities  to  minute  particles  of  garnet,  and  the  German 
water  hone.  Both  of  these  stones  are  sold  at  the  present 
time. 

The  well-known  Arkansas  and  Ouachita  (Washita)  stones 
were  discovered  in  Arkansas  in  the  year  1815.  These  are 
found  in  the  foot-hills  of  the  Ozark  Mountains.  There  are 
two  varieties  of  Arkansas  stones;  hard  Arkansas  and  soft 
Arkansas.  The  former  consists  of  99^  per  cent,  pure 
silica,  being  composed  of  very  small  particles  of  hexagonal- 
shaped  crystals  to  which  it  owes  its  cutting  qualities. 
This  stone  is  widely  used  by  watchmakers,  engravers,  tool- 
makers,  etc.,  for  putting  a  very  fine  edge  on  cutting  tools. 
Soft  Arkansas  stones,  although  not  as  hard  as  the  former 
variety,  are  freer  cutting,  therefore  they  are  the  choice  of 
the  carpenter,  cabinet  maker  and  pattern  maker  for  putting 
the  correct  cutting  edge  on  chisels,  plane  irons,  etc. 

35 


ABRASIVES  AND  ABRASIVE  WHEELS 

Another  famous  natural  stone  is  the  Indian  Pond  scythe 
stone,  discovered  in  New  Hampshire  in  the  year  1821. 
Upon  this  discovery  was  founded  the  well-known  business 
of  the  Pike  Manufacturing  Company,  whose  goods  are 
known  to  mechanics  throughout  the  world.  Several  grades 
of  fine  sandstone  are  used  in  making  sharpening  stones 
for  various  purposes,  scythe  stones,  axe  stones,  etc.,  large 
deposits  being  located  in  Ohio.  As  a  matter  of  fact,  this 
state  furnishes  many  varieties  of  natural  sharpening  stones 
such  as  the  Hindustan,  Queer  Creek  arid  Chagrin  Falls 
brands.  These  are  all  excellent  stones  and  find  a  ready 
market  for  purposes  to  which  they  are  adapted. 

TRIPOLI 

Tripoli  is  a  trade  name  given  to  a  yellowish  abrasive 
material  which  results  from  the  leaching  of  calcareous 
material  from  limestones  and  cherts.  This  material  is  also 
often  called  rotten  stone.  It  is  found  principally  in  Illinois 
and  Missouri.  For  abrasive  purposes,  it  is  used  principally 
for  "cutting  down"  before  polishing  soft  metals.  It  is  put 
on  the  market  in  the  form  of  cakes,  being  mixed  with  tallow 
and  compressed. 

PUMICE 

Pumice  is  of  volcanic  origin,  being  an  igneous  rock  which 
was  cooled  so  quickly  that  it  did  not  have  time  to  crystallize. 
It  sometimes  contains  impurities,  such  as  feldspar  and 
hornblende,  which  diminish  the  general  value  of  the 
material  as  an  abrasive,  as  the  impurities  leave  deep  scratches 
owing  to  their  hard  nature.  Natural  pumice  is  found  in 
California,  Kansas,  Nebraska,  Idaho,  South  Dakota  and 
Utah  in  this  country  while  much  of  the  imported  article 
conies  from  various  islands  in  the  Mediterranean  Sea. 
As  an  abrasive,  pumice  is  used  principally  for  very  fine 
varnish  rubbing  and  in  the  manufacture  of  metal  polishes. 

36 


CHAPTER  TWO 

ARTIFICIAL   ABRASIVES 

Various  artificial  abrasives — Their  physical  and  chemical  properties — Their 
commercial  application — Methods  and  processes  employed  in  the  pro- 
duction of  artificial  abrasives — Carborundum — Alundum — Aloxite — Boro- 
Carbone — Oxalumina — Adamite — Crystolon,  etc. — Relative  hardness  and 
abrasive  efficiency  of  various  materials — Artificial  production  of  precious 
stones — Their  abrasive  properties — Other  artificial  abrasives  and  their 
production — Experimental  work — Electro-thermic  processes — Production 
of  rouge  and  crocus — Diamonds  and  crushed  steel — Angular  grit. 

UNDER  this  heading  can  be  included  all  grinding  and 
polishing  materials  produced  by  the  arts  of  man;  the 
most  commonly  used  being  divided  into  two  classes,  carbide 
of  silicon  abrasives,  the  original  of  which  is  Carborundum, 
and  artificial  corundum,  which  material,  in  the  form  of 
precious  stones,  has  been  made  for  more  than  seventy  years. 

In  reality,  the  artificial  corundum  of  today,  sold  under  va- 
rious trade  names,  such  as  Aloxite,  Alundum,  Boro-Carbone, 
Oxalumina,  etc.,  is  an  indirect  outgrowth  of  the  experiments 
of  other  days,  wherein  scientific  investigators  had  to  con- 
tent themselves  with  making  artificial  rubies  and  sapphires, 
while  vainly  striving  to  produce  the  artificial  diamond. 

To  class  rouge  and  crocus  as  abrasives  may  seem  rather 
far  fetched  on  first  thought,  but  it  must  be  borne  in  mind 
that  while  these  materials  are  used  for  polishing  purposes 
only,  their  mission  is  accomplished  through  abrasion,  since 
the  finest  mechanically  finished  surface  possible  to  produce, 
when  viewed  under  a  powerful  microscope,  is  seen  to  consist 
of  a  multitude  of  fine  scratches. 

Crushed  steel  and  chilled  iron  are  abrasives  in  the  true 
sense  of  the  word.  The  former  is  used  for  grinding  and  the 

37 


ABRASIVES  AND  ABRASIVE  WHEELS 

latter  for  sand  blasting,  which  is  a  process  of  removing 
superfluous  material  by  abrasive  action. 

Carborundum  is  undeniably  the  best  known  and,  for 
many  purposes,  the  most  useful  of  all  the  artificial  abrasives; 
indeed,  it  is  often  called  the  father  of  them  all,  since  its 
introduction  into  the  mechanical  world  gave  electro- 
chemical engineers  an  impetus  to  produce  competitive 
material. 

For  the  sake  of  clearness,  the  various  well-known  artificial 
abrasives  will  be  considered  in  chronological  order,  Car- 
borundum being  at  the  head  of  the  list  as  it  was  the  first 
artificial  abrasive  to  be  recognized  commercially. 

CARBORUNDUM 

Carborundum  is  a  trade  name  given  to  carbide  of  silicon, 
a  substance  discovered  during  the  year  1891  by  Edward  G. 
Acheson.  It  can  truly  be  called  the  most  unique  of  all 
abrasives  as  it  has  never  been  found  in  nature,  therefore 
it  is  not  an  imitation  of  nature's  work,  but  a  distinct  creation 
in  a  class  by  itself.  It  is  a  chemical  combination  of  the 
two  elements  carbon  and  silicon,  its  chemical  formula 
being  SiC. 

The  raw  materials  entering  into  the  manufacture  of 
Carborundum  are  coke,  sand,  salt  and  sawdust.  Coke 
supplies  the  element  carbon,  while  the  element  silicon  is 
derived  from  the  sand.  The  object  of  the  sawdust  is  simply 
to  make  the  mass  porous,  thereby  permitting  the  gases 
generated  during  the  burning  operation  a  free  passage  to 
the  open  air.  The  object  of  the  salt  is  to  eliminate  im- 
purities such  as  iron,  etc.  As  the  salt  volatilizes;  it  im- 
pregnates the  whole  mass,  taking  up  impurities  in  the  form 
of  chlorides. 

The  Carborundum  furnaces  used  at  the  present  time  are 
fifty  feet  long,  ten  feet  wide,  and  five  feet  high.  The 
original  furnaces,  however,  were  somewhat  smaller.  Both 
types  are  of  open  construction,  the  sides  and  ends  being 


CARBORUNDUM 


built  of  brick.  The  end  walls  are  approximately  two  feet 
thick,  through  which  run  the  terminals  for  the  electric  cur- 
rent. These  terminals  are  made  of  carbon  rods  three  feet 
long  and  three  inches  in  diameter,  arranged  parallel  in 
bundles  of  sixty,  the  spaces  between  the  rods  being  packed 
tightly  with  graphite.  At  the  outer  ends  of  the  rods, 
copper  terminals  are  let  in,  which,  in  turn,  are  connected 
to  a  large  copper  cap.  Current  is  supplied  by  means  of 
cables  from  overhead  bus  bars. 

In  charging  the  Carborundum  furnaces  preparatory  to 
burning,    a   mixture   of   thirty-four  parts   coke,    fifty-four 


Fig.  i. — Carborundum  furnace  charged  with  raw  material,  ready  for  burning. 

parts  sand,  ten  parts  sawdust  and  two  parts  salt  is  used. 
The  materials  are  thoroughly  mixed  and  brought  to  the 
furnaces  by  means  of  mechanical  conveyors.  Enough  of 
this  mixture  is  placed  in  the  furnace  to  bring  the  upper 
layer  level  with  the  ends  of  the  electrodes.  A  trench  is  now 
made  between  the  terminals,  wherein  a  core  of  granulated 
coke  is  laid.  The  object  of  the  coke  is  to  allow  a  free  pas- 
sage for  the  electric  current.  More  of  the  material  is  now 
introduced  and  built  up  in  the  form  of  a  mound  as  shown 
in  Fig  i. 

39 


ABRASIVES  AND  ABRASIVE  WHEELS 

An  alternating  current  of  190  volts  and  6,000  amperes 
is  now  turned  on.  As  the  mass  heats,  the  resistance  to  the 
current  gradually  diminishes,  and  after  about  four  hours' 
operation,  it  remains  constant  at  125  volts  and  6,000 
amperes.  The  sawdust,  of  course,  burns  away  first,  after 
which  carbon  monoxide  is  given  off.  This  burns  freely  at  the 
sides  and  top  of  the  furnace  with  a  yellow  flame.  As  the 
process  of  burning  progresses,  the  mass  shrinks  somewhat, 
which  necessitates  adding  more  raw  material.  Occasionally 
the  phenomenon  of  "blowing"  occurs,  which  makes  the 
furnace  look  not  unlike  a  miniature  volcano.  This  is  caused 
by  an  over-charge  of  gas  suddenly  igniting  and  bursting 
through  the  top  crust  of  the  charge.  After  a  period  of 
about  thirty-six  hours,  the  burning  operation  is  completed. 
Several  furnaces  are  in  the  process  of  burning  at  the  same 
time,  being  started  at  intervals  of  a  few  hours  apart.  The 
object  of  this  is  to  insure  constant  production  as  well  as 
the  economical  use  of  current.  The  current  is  carefully 
watched,  at  all  times  by  an  electrical  engineer  especially 
trained  on  electric-furnace  work.  This  is  quite  essential, 
otherwise  a  uniform  product  would  be  an  impossibility. 

After  the  burning  is  completed,  the  furnace  is  allowed  to 
cool  for  twenty-four  hours,  after  which  it  is  broken  open, 
^he  top  crust,  which  is  in  a  comparatively  unaltered  state, 
is  removed,  exposing  a  layer  of  amorphous  carbide  of  sili- 
con under  which  lies  the  pure  crystallized  Carborundum. 
Next  comes  a  mixture  of  Carborundum  and  graphite  and, 
last  of  all,  the  core.  The  intense  heat,  estimated  at  ap- 
proximately 7,500°  Fahrenheit,  transforms  the  core  into 
practically  pure  graphite.  The  amorphous  carbide  of  sili- 
con previously  mentioned  was  at  first  considered  of  no 
value  and  consequently  thrown  away.  Later  scientific  in- 
vestigation, however,  showed  that  it  possessed  a  high 
refractory  value.  At  the  present  time  it  finds  a  ready 
market  as  a  refractory  material  for  lining  furnaces  subjected 
to  high  heats  of  long  duration. 

The  Carborundum  crystals,  while  well  developed,  are 
40 


CARBORUNDUM 

not  regular  in  appearance,  some  being  hexagonal  and  others 
rhombohedral.  The  crystals  have  no  lines  of  cleavage, 
breaking  with  a  distinct  crystalline  fracture,  invariably 
leaving  sharp  cutting  edges. 

Carborundum  crystals  are  of  various  colors,  being  truly 
beautiful  from  an  artistic  point  of  view;  coal  black,  deep 
brown,  light  green,  pale  blue,  deep  blue  a'nd  purple  are  all 
intermingled  in  a  gorgeous  riot  of  colors  seldom  equaled  in 
nature.  In  the  early  days  of  the  industry,  green  Carbo- 
rundum predominated  and  at  present  many  are  of  the  opin- 
ion that  green  Carborundum  is  superior  in  cutting  qualities 
to  specimens  of  other  colors.  Actual  tests,  however,  con- 
ducted by  abrasive  engineers,  have  proven  beyond  all  reason- 
able doubt  that  the  above  theory  is  absolutely  groundless, 
the  color  being  the  result  of  oxidation. 

On  Moh's  scale  of  hardness,  Carborundum  is  placed  be- 
tween nine  and  ten.  It  is  probably  nearer  ten  than  nine 
as  Carborundum  has  been  known  to  scratch  rubies,  sapphires, 
and  diamonds.  Compared  with  other  abrasives,  Carbo- 
rundum is  comparatively  light,  its  specific  gravity  being 
approximately  3.18.  This  factor  should  not  be  under- 
estimated since  the  centrifugal  force  of  a  revolving  body 
is  proportional  to  the  square  of  the  velocity.  Thus,  wheels 
running  at  the  high  speeds  recommended  in  present-day 
grinding  practice  are  under  a  severe  centrifugal  strain, 
and  it  is  apparent  that  the  lightest  abrasive  makes  the  safest 
wheel.  • 

Fig.  2  gives  a  good  idea  of  the  appearance  of  Carborundum 
as  it  comes  from  the  furnace,  the  photograph  being  taken 
after  the  outer  layers  and  core  had  been  removed.  As  this 
material  looks  like  the  products  of  the  mine  and  quarry,  the 
question  is  sometimes  asked,  "Why  is  carbide  of  silicon  not 
found  in  nature?"  The  only  reasonable  answer  the  writer 
can  give  is  that  the  degree  of  heat  at  which  both  carbide  of 
silicon  and  graphite  are  formed  is  so  near  the  same  temper- 
ature that  nature  seemed  content  to  produce  graphite  alone. 

An  interesting  feature  of  the  production  of  Carborundum, 
41 


ABRASIVES  AND  ABRASIVE  WHEELS 


from  the  electrical  engineer's  point  of  view,  at  least,  is  the 
form  of  circuit  breaker  used  in  making  and  breaking  the 
heavy  current.  As  this  amounts  to  750  kilowatts  it  is  seen 
that  the  ordinary  form  of  contact  switch  would  be  destroyed 
in  short  order.  To  overcome  this  difficulty,  a  special  circuit 


Fig.  2. — How  Carborundum  looks  as  it  comes  from  the  furnace. 

breaker  of  the  water-regulator  type  is  used.  This  consists 
of  a  number  of  iron  plates  working  in  a  salt-water  solution. 

Thejarge  masses  of  crystals  produced  in  the  Carborundum 
furnace  are  reduced  in  crushing  machines  of  the  dry-pan 
muller  type,  illustrated  in  Fig.  3.  Under  the  weight  of 
the  rolls  (two  tons  each)  and  the  rotary  motion  of  the  pan 
(thirty  revolutions  per  minute),  the  Carborundum  masses 
are  rapidly  crushed  to  small  crystals.  These  range  all  the 
way  from  very  coarse  to  an  impalpable  powder.  Although 
the  crushing  rolls  are  made  of  manganese  steel,  they  do  not 
last  long,  owing  to  the  abrasive  action  of  the  Carborundum 
grains,  a  pair  lasting  but  six  months  at  the  longest. 

Carborundum  as  it  comes  from  the  furnace  is  impreg- 
nated with  a  small  amount  of  iron  oxide  taken  from  the 
sand  and  other  minor  impurities  derived  from  the  coke. 
To  eliminate  these  the  crystals  are  transferred  to  wooden 
vats,  lined  with  lead,  where  they  are  lixiviated  with  strong 

42 


CARBORUNDUM 

sulphuric  acid.  The  crystals  are  next  washed  in  long 
wooden  troughs,  the  washing  being  passed  through  settling 
tanks  which  help  to  separate  the  grains  from  the  fine  powder. 
The  crystals  are  now  thoroughly  dried  by  coke  fires,  after 


Fig.  3. — Muller  type  of  crusher  used  in  preparing  Carborundum. 

which  they  are  ready  for  "grading,"  or  "screening,"  as  this 
operation  is  sometimes  termed. 

The  screening  machine,  as  shown  in  Fig.  4,  consists  of  a 
series  of  screens  set  on  a  slight  incline  with  their  ends  meet- 
ing. The  fine  screens  are  made  of  a  superior  quality  of 
milling  silk,  while  the  coarser  type  are  made  of  brass  wire. 
The  Carborundum  grains  are  fed  on  the  screen  at  the  high 
end,  and  a  vibratory  motion,  imparted  to  the  screen  frame, 
causes  them  to  journey  downward.  In  passing  over  the 
screens,  they  find  an  outlet  suitable  for  their  size.  After 
passing  through  the  screens,  the  grain  flows  into  receptacles 
placed  under  the  delivery  openings  as  the  illustration  shows. 
The  screens  vary  from  six  meshes  to  the  inch  to  two  hundred 
and  twenty  meshes  to  the  inch. 

Owing  to  the  abrasive  action  of  the  grain  the  screens 
wear  readily.  Thus  care  has  to  be  exercised  to  insure  uni- 
form grading.  This  is  accomplished  by  frequently  testing 

43 


ABRASIVES  AND  ABRASIVE  WHEELS 

samples  that  have  passed  through  the  several  screens  in 
testing  machines  carrying  master  screens.  When  the  grains 
are  out  of  grade,  it  is  a  sign  that  the  screen  through  which 
it  passed  has  worn  to  the  extent  of  warranting  renewal. 


Fig.  4. — Screening  machines  used  in  grading  Carborundum. 

This  is  promptly  attended  to  and  all  over-size  material 
regraded. 

It  is  not  practicable  to  grade  Carborundum  finer  than 
two  hundred  and  twenty  by  the  screening  method.  There- 
fore another  method  is  used  for  grading  the  powders  as  they 
are  termed.  In  this  system  the  fine  powder  is  carried  by  a 
stream  of  water  through  a  series  of  settling  tanks.  In  pass- 
ing through  the  tanks,  one  after  another,  the  heavier 
grains  sink.  Thus,  the  last  tank  contains  nothing  but  the 
very  finest  powder.  At  the  works  of  The  Carborundum 
Company,  the  following  grains  and  powders  are  carried  in 
stock:  6,  8,  10,  12,  14,  16,  20,  24,  30,  36,  40,  50,  60,  70,  80, 
90,  100,  120,  150,  180,  220  and  powders  F,  FF,  FFF. 

44 


CARBORUNDUM 

Carborundum  is  very  hard,  exceedingly  sharp,  and  when 
made  into  grinding  wheels,  it  furnishes  a  highly  efficient 
abrasive  for  the  grinding  of  materials  of  comparatively 
low  tensile  strength,  such  as  gray  iron,  chilled  iron,  brass, 
bronze,  marble,  pearl,  bone,  horn,  etc.  In  grain  and  pow- 
der form,  Carborundum  is  extensively  used  for  lapidary 
work,  valve  grinding,  plate-glass  beveling,  stone  finishing, 
etc.  It  is  sometimes  used  on  "set  up"  wheels  for  polishing 
cast  iron,  but  owing  to  the  fact  that  considerable  skill  is 
required,  both  in  preparing  the  glue  and  in  covering  the 
wheels,  the  above  practice  has  not  become  universal. 

Carborundum  coated  paper  and  cloth  enjoy  an  immense 
sale  in  the  boot-and-shoe  industry,  where  they  are  used 
for  such  operations  as  fore-part  buffing,  heel  breasting, 
heel  scouring,  etc.  In  the  wood-working  industries,  how- 
ever, Carborundum  paper  does  not  show  efficiency  over 
flint  and  garnet  paper  as  its  sharp  nature  causes  the  coated 
paper  to  fill  up  very  readily. 

In  the  leather-manufacturing  industries,  Carborundum 
is  used  in  a  barrel-shaped  wheel  form,  for  the  "wet  wheeling  " 
of  leather,  as  this  operation  on  skins  is  termed.  In  grain 
form,  it  is  used  on  a  special  shaped  cylinder  for  "buck- 
tailing,"  while  in  the  form  of  paper  and  cloth,  it  is  used  for 
various  finishing  operations. 

It  is  often  stated  that  Carborundum  will  not  grind  steel 
economically,  but  this  statement  is  erroneous.  At  one 
time  The  Carborundum  Company  sold  a  large  number  of 
wheels  to  the  lumber  industry  for  saw  gumming.  As  a 
matter  of  fact,  this  is  an  operation  calling  for  a  very  cool 
and  rapid-cutting  wheel.  The  writer  has  used  Carborundum 
wheels  for  the  cylindrical  grinding  of  cold  rolled  and  ma- 
chine steel  with  excellent  results.  Not  only  did  the  wheels 
produce  an  excellent  finish,  but  they  were  very  uniform  in 
grade,  a  feature  not  at  all  common  some  ten  years  ago. 
The  writer  has  seen  Carborundum  wheels  used  for  auto- 
mobile crank-shaft  grinding  by  one  of  the  largest  manu- 
facturers in  the  Middle  West.  The  results  were  satisfac- 

45 


ABRASIVES  AND  ABRASIVE  WHEELS 

tory,  Carborundum  being  preferred  to  all  other  makes  of 
wheels. 

It  must  be  considered  that  the  above  instances  happened 
some  years  ago,  before  the  high  development  and  accurate 
grading  of  manufactured  alumina  abrasives,  which  at  the 
present  time  show  higher  efficiency  on  steel  grinding  than 
is  possible  to  attain  with  Carborundum.  The  above  state- 
ments are  made  simply  to  show  that  at  one  time  in  the  his- 
tory of  grinding,  Carborundum  held  its  own  on  steel. 

Why,  then,  does  not  Carborundum,  which  is  acknowledged 
to  be  the  hardest  and  sharpest  of  all  abrasives,  both  natural 
and  artificial,  show  high  efficiency  on  steel  grinding?  This 
is,  at  best,  a  hard  question  to  answer  and  one  upon  which 
opinions  are  at  great  variance.  The  writer's  opinion,  based 
upon  many  years  of  observation,  close  study,  and  prac- 
tical application,  is  that  if  Carborundum  was  not  quite  so 
hard,  and  broke  with  a  conchoidal  instead  of  a  crystalline 
fracture,  it  would  eventually  drive  the  alumina  abrasives 
out  of  the  market. 

The  above  opinion  can  be  called  pure  speculation  without 
a  suitable  hypothesis,  therefore  it  is  open  to  question. 
However  this  may  be,  it  is  set  down  for  what  it  is  worth, 
for  opinions,  no  matter  how  theoretical  they  may  appear, 
possess  some  merit,  at  least  until  they  have  been  dis- 
proved by  actual  demonstration,  and  as  it  is  an  impossi- 
bility to  produce  the  type  of  Carborundum  described,  the 
above  theory  may  be  as  rational  as  any  other. 

The  name  Carborundum  is  registered  as  a  trade  mark, 
thus  it  is  the  sole  property  of  The  Carborundum  Company. 
It,  however,  grinding  wheels  are  made  of  Carborundum, 
no  matter  by  whom,  they  can  lawfully  be  sold  as  genuine 
Carborundum  wheels. 

OTHER  CARBIDE  OF  SILICON  ABRASIVES 

A  carbide  of  silicon  abrasive  called  "  Carbosolite  "  is  made 
in  Germany.  It  has  been  sold  in  this  country  to  a  limited 

46 


ARTIFICIAL  CORUNDUM 

extent,  chiefly  in  the  granite-finishing  business.  It  is 
mostly  of  a  dark-gray  color  and  it  is  not  considered  as  pure 
as  Carborundum.  Aside  from  the  granite  trade,  a  limited 
amount  of  this  material  is  made  into  grinding  whe^s. 

Crystolon  is  a  trade  name  given  to  a  carbide  of  silicon 
abrasive  made  by  Norton  Company  at  their  electric- 
furnace  plant  in  Chippawa,  Canada.  It  is  made  by  practi- 
cally the  same  method  used  in  producing  Carborundum; 
the  same  raw  material  forming  the  ingredients.  It  was 
first  puu  on  the  market  about  seven  years  ago,  and  at 
the  present  time  it  enjoys  a  large  sale,  both  in  the  form  of 
wheels  and  grain. 

The  Abrasive  Company  of  Philadelphia  market  grinding 
wheels  made  of  carbide  of  silicon,  calling  the  same  "Elec- 
trolon."  This  material  is  an  electric-furnace  product,  being 
made  of  selected  materials,  the  grain  being  specially  treated 
before  being  incorporated  into  grinding  wheels/  This  ma- 
terial was  first  put  on  the  market  during  the  year  1914 
and  it  is  considered  by  many  large  consumers  of  grinding 
wheels  to  be  a  very  efficient  abrasive. 

ARTIFICIAL  CORUNDUM 

As  stated  at  the  beginning  of  this  chapter,  artificial 
corundum  has  been  produced  for  more  than  seventy  years 
and  in  considering  the  subject  in  the  abstract,  a  little  light 
thrown  on  the  experimentalists  of  other  days  may  not  be 
out  of  place  at  the  present  time. 

It  is  a  well-known  fact  among  those  conversant  with  the 
values  of  precious  stones  that  a  true  Oriental  ruby,  of  fine 
color  and  flawless,  is  worth  more,  carat  for  carat,  than 
the  finest  diamonds  of  Brazil  or  South  Africa.  The  term 
ruby  is  often  misconstrued  to  embrace  the  spinel  or  balas 
ruby.  Indeed,  the  famous  "ruby"  set  in  the  Maltese  cross 
in  front  of-  the  imperial  state  crown  of  England  is  in  reality 
a  spinel.  It  is,  of  course,  possible  for  experts  to  readily 
distinguish  the  difference  between  true  and  spinel  rubies,  but 

47 


ABRASIVES  AND  ABRASIVE  WHEELS 

since  the  ruby  is  nothing  more  or  less  than  pure  crystallized 
alumina,  colored  with  a  small  quantity  of  chromium,  it  is 
evident  that  a  laboratory  product  of  the  above  materials 
is  a  true  synthesis  of  the  ruby.  It  is  as  much  entitled  to  the 
name  as  the  choicest  specimens  of  nature  from  the  Mandalay 
district  of  Upper  Burma,  where  the  finest  rubies  have  been 
found. 

In  the  year  1837,  M.  A.  A.  Gaudin  successfully  made 
true  rubies  by  fusing  alum  in  a  carbon  crucible  at  a  very 
high  temperature,  a  little  chromium  being  added  to  impart 
the  desired  color.  The  rubies,  while  of  a  very  small  size, 
hardly  visible  to  the  naked  eye,  proved  that  it  was  within 
the  means  of  science  to  produce  corundum  artificially. 

J.  J.  Ebelmen's  experiments  during  the  year  1847  resulted 
in  the  artificial  production  of  the  white  sapphire  and  rose- 
colored  spinel.  The  process  consisted  of  fusing  the  desired 
constituents  at  high  temperature  in  boracic  acid.  He  also 
produced  the  ruby  by  using  borax  as  a  solvent. 

Not  until  the  year  1877,  however,  was  it  proved  possible 
to  produce  crystallized  artificial  alumina  of  a  size  suitable  for 
cutting  into  small  stones,  the  process  being  the  result  of 
experiments  on  the  part  of  E.  Fremy  and  C.  Feil.  The 
process  used  was  as  follows :  By  the  fusion  of  lead  oxide  and 
alumina  in  a  fire-clay  crucible,  lead  aluminate  was  formed. 
Silica  enters  into  the  composition  of  fire  clay,  and  under 
the  influence  of  high  temperature,  the  silica  of  the  crucible 
gradually  decomposes  the  lead  aluminate,  forming  lead 
silicate,  which  remains  in  a  liquid  state  while  the  alumina 
crystallizes  as  white  sapphire.  By  mixing  in  a  small  amount 
of  chromium,  rubies  were  formed.  The  experiments  of 
Sainte-Claire  Deville,  Caron,  Eisner,  Debray,  and  De 
Senarmont,  too  lengthy  to  be  described  fully  here,  did 
much  toward  reducing  the  art  of  producing  artificial  corun- 
dum to  an  exact  science. 

So  much  for  the  experimentalists  of  other  days.  They 
did  not  attempt  to  produce  artificial  corundum  for  abrasive 
purposes,  to  be  sure,  such  a  possibility  being  undreamed  of 

48 


ARTIFICIAL  CORUNDUM 

in  their  day.  The  fact  remains,  however,  that  their  investi- 
gations were  of  value  as  by  their  means  it  was  shown  con- 
clusively that  it  was  possible  to  produce  artificial  corundum. 

One  of  the  first  inventors  to  achieve  success  in  the  manu- 
facture of  an  artificial  abrasive  of  the  alumina  type  was 
Franz  Hasslacher  of  Frankfurt-on-Main,  Germany.  As 
stated  elsewhere,  emery  contains  a  high  percentage  of  iron 
oxide,  which  possesses  no  abrasive  value,  and  aside  from  this 
fact  most  specimens  of  emery  are  hydrous,  often  containing 
as  high  as  5  per  cent,  of  combined  water,  which  causes  trouble 
in  the  kilns  where  wheels,  in  which  this  emery  is  incor- 
porated, are  made  by  the  vitrified  process.  The  above- 
named  inventor  was  granted  a  patent  for  changing  natural 
emery  into  iron-and-water-free  corundum  (German  patent 
No.  85,021,  issued  Nov.  20,  1894),  the  method  of  procedure 
being  as  follows: 

Crushed  emery  ore  and  charcoal  or  coke  are  first  mixed 
together,  the  percentage  of  the  latter  being  equal  to  the 
proportion  of  iron  oxide  contained  in  the  emery  ore.  This 
mixture  is  then  placed  in  an  electric  furnace,  an  illustration 
of  which  is  shown  in  Fig.  5.  The  furnace  consists  of  fire- 
brick walls  (A) ,  supported  by  the  uprights  (H) ,  the  electric 
current  being  transmitted  by  the  carbons  (C) . 

In  charging  the  furnace  the  opening  at  the  bottom  (D) 
is  closed  by  means  of  a  glass  plate  (P)  and  the  furnace  filled 
with  the  emery-and-coke  mixture  until  the  top  of  the  mass 
is  level  with  the  center  of  the  carbons.  The  carbons  are 
placed  about  i->£  inches  apart,  the  space  between  them 
being  packed  with  a  few  lumps  of  coke.  The  furnace  is 
now  completely  filled  and  heaped  up  as  shown  at  (S). 

An  alternating  current  of  300  amperes  at  a  pressure  of 
no  volts  is  now  turned  on,  under  the  influence  of  which 
the  pieces  of  coke  between  the  carbons  are  brought  up  to 
incandescence,  which  causes  the  surrounding  emery  to 
assume  a  molten  state.  The  pieces  of  coke  are  soon  ab- 
sorbed and  an  electric  arc  established  between  the  terminals, 
the  presence  of  which  is  proven  by  a  loud  buzzing  sound. 

49 


ABRASIVES  AND  ABRASIVE  WHEELS 

Carbon  monoxide  gas  escapes  through  the  mass,  burning 
with  a  blue  flame.  The  presence  of  this  gas  indicates  that 
the  iron  oxides  are  in  the  process  of  reduction.  A  large 
mass  of  molten  emery  soon  forms  about  the  electrodes, 


Fig.  5. — Hasslecher's  furnace  for  making  artificial  corundum. 

the  furnace  walls  being  protected  by  the  surrounding,  un- 
melted  material  as  the  illustration  shows.  When  a  suf- 
ficient amount  of  emery  has  been  melted,  the  glass  plate 
fuses,  causing  the  emery  to  run  through  to  the  floor  in  a 
dazzling,  white-hot  stream. 

At  this  point,  the  top  crust  is  broken  in,  whereat  the 
descending  crust  of  emery  cools  the  molten  emery  around 
the  opening,  causing  the  same  to  close.  The  furnace  is 
then  charged  again  and  the  process  continued.  In  about 
fifteen  minutes,  the  molten  emery  again  breaks  through. 
Thus  the  process  can  be  continued  as  long  as  convenient. 

The  resulting  product  is  fairly  well  crystallized  alumina, 
running  from  white  to  blue  in  color,  possessing  a  luster 
not  unlike  that  of  quartz.  This  material,  being  free  from 
iron,  possesses  a  higher  abrasive  efficiency  than  emery 
and  for  some  purposes  it  gives  excellent  results.  It  has  been 

5° 


ARTIFICIAL  CORUNDUM 

used  in  this  country  to  quite  an  extent,  but  at  the  present 
time,  and  in  fact  for  the  last  fifteen  years,  it  has  not  been  able 
to  successfully  compete  with  American-made  products. 

Another  process  for  making  artificial  alumina  was  patented 
by  Dr.  G.  Dollner  of  Rixdorf,  Germany  (German  patent 
No.  97,408,  issued  Feb.  28th,  1897).  The  method  is  quite 
simple  and  easily  carried  out,  consisting  of  mixing  crushed 
aluminum  with  oxides,  peroxides  and  other  metallic  com- 
pounds with  oxygen.  This  mixture,  when  ignited,  owing  to 
the  high  combustion  temperature  of  aluminum,  reacts  in  an 
endothermic  manner  causing  the  formation  of  oxide  of  alumina. 
This  phenomenon  is  accompanied  by  the  separation  of  the 
metals,  the  oxides  and  peroxides  of  which  were  used. 

In  the  reaction,  the  oxide  of  alumina  is  brought  to  a 
state  of  fusion,  and,  on  cooling,  it  is  characterized  by  extreme 
hardness.  In  his  patent  specifications,  the  inventor  claims 
that  this  material  is  of  a  degree  of  sufficient  hardness  to 
replace  diamonds  for  technical  purposes,  and  further  states 
that  it  is  superior  to  other  artificial  abrasives  as  by  this 
process  grinding  wheels  can  be  prepared  in  solid  blocks — 
that  is  a  grinding  wheel  produced  without  a  bonding 
material.  Whether  or  not  this  has  been  carried  out  suc- 
cessfully the  -writer  cannot  state.  Even  if  it  were  possible, 
however,  such  a  wheel  would  be  of  one  grade  only,  thus 
its  field  of  usefulness  would  be  limited. 

It  may  be  well  at  this  time  to  consider  an  abrasive  called 
Corubin,  which  is  a  by-product  resulting  from  the  manu- 
facture of  chromium  by  the  Goldschmidt  Thermit  alumino- 
thermic  process.  The  above  process  is  one  for  making 
metallic  chromium  through  endothermic  action,  the  slag  or 
by-product  of  which  forms  an  excellent  abrasive  material 
as  the  following  analysis  shows. 

Chromium 13 . 2  per  cent. 

SiO2 3.08      " 

A12O3 71-65      " 

Fe 2.00      " 

CaO Trace 

MgO 1.35      " 


ABRASIVES  AND  ABRASIVE  WHEELS 

From  the  above,  it  is  seen  that  this  material  is  composed 
chiefly  of  alumina  and  chromium,  the  percentage  of  alu- 
mina being  high  enough  to  form  an  efficient  abrasive,  while 
the  amount  of  chromium  contained  renders  the  abrasive 
very  hard  and  tough. 

In  the  manufacture  of  other  metals  by  the  Goldschmidt 
Thermit  process,  other  slags  are  obtained  being  only  slightly 
inferior  in  abrasive  efficiency  to  Corubin.  The  writer  is 
informed  on  good  authority  that  these  abrasives  are  giving 
satisfaction,  owing  to  the  fact  that  several  thousand  tons 
of  them  are  sold  annually  to  responsible  abrasive-wheel 
manufacturers  in  this  country.  Large  quantities  of  Corubin 
are  used  abroad  in  the  manufacture  of  lenses,  wherein  the 
abrasive  is  used  to  grind  the  glass,  and  in  other  abrasive 
work. 

That  the  experimentalists  made  great  strides  in  perfect- 
ing methods  for  the  manufacture  of  artificial  abrasives 
(after  Acheson  and  The  Carborundum  Company  proved  to 
the  world  that  there  was  a  ready  market  for  an  artificial 
abrasive)  no  one  will  deny.  The  artificial  corundum  made 
previous  to  the  year  1900,  however,  was  incomplete  in 
that  it  lacked  what  we  term  at  the  present  day  abrasive 
temper.  We  all  know  that  high-carbon  steel,  or  tool  steel 
as  it  is  called,  possesses  a  valuable  characteristic  inasmuch 
as  it  can  be  made  exceedingly  hard  by  heating  it  red  hot 
and  suddenly  cooling  it  by  immersion  in  water,  or  a  brine 
solution.  Further,  by  tempering  it,  or  drawing  the  color 
as  the  smith  says,  we  get  various  degrees  of  temper  for  in- 
numerable purposes;  a  very  hard  steel  for  razors,  a  some- 
what softer  material  for  machine  reamers,  softer  still  for 
lathe,  tools,  and  yet  softer  for  cold  chisels  and  axes. 

A  piece  of  tool  steel  that  has  been  hardened  but  not  drawn, 
is  very  brittle,  thus  its  field  is  limited.  For  an  illustration, 
a  lathe  tool,  a  pair  of  scissors,  or  an  axe  thus  treated  would 
be  useless — the  lathe  tool  would  crumble  away  as  soon  as 
it  was  brought  in  contact  with  the  piece  of  work  to  be  turned, 
the  scissors  would  break  the  first  time  they  were  dropped 

52 


BAUXITE 

on  the  floor,  while  the  axe  would  fly  to  pieces  at  the  first 
stroke  of  the  woodsman.  Thus,  it  is  seen,  that  the  character- 
istic of  temper  is  what  gives  tool  steel  its  immense  value 
in  the  arts  and  sciences. 

To  complete  the  parallel  we  will  now  consider  artificial 
corundum,  which,  as  originally  made,  was  very  hard  and 
useful  in  a  limited  field  only.  It  is  evident  that  if  means 
could  be  found  whereby  the  temper  of  the  material  in 
question  could  be  controlled,  its  usefulness  would  be  in- 
creased a  thousandfold. 

This  has  been  successfully  accomplished  and  the  credit 
is  due  to  an  American,  Charles  B.  Jacobs  (no  relation  to 
the  writer),  who  in  the  year  1900  obtained  a  process 
patent  for  manufacturing  an  abrasive  from  bauxite  and 
tempering  the  same  to  a  degree  of  hardness  suitable  for 
abrasive  purposes.  Briefly  stated,  Mr.  Jacobs'  process  con- 
sists of  fusing  bauxite  in  an  electric  furnace  of  the  arc  type 
and  cooling  the  resultant  alumina  oxide  in  a  manner  to 
impart  the  desired  degree  of  temper. 

Before  considering  Mr.  Jacobs'  process,  it  will  be  of  ad- 
vantage at  this  point  to  touch  briefly  on  the  material  bauxite 
as  we  will  have  occasion  to  refer  to  it  several  times  later. 


BAUXITE 

Bauxite  is  a  clay-like  mineral,  or  rather  a  combination  of 
minerals,  containing  among  other  constituents  alumina 
oxide,  iron  oxide,  silica  and  titanic  acid.  It  is  taken  to  be 
a  decomposition  product  of  igneous  rock.  It  was  first  dis- 
covered in  France  as  long  ago  as  the  year  1821  by  P. 
Berthier,  who  called  it  alumina  hydratee  de  Beaux.  The 
present  name  of  bauxite  was  given  to  the  material  in  ques- 
tion by  E.  H.  Sainte-Claire  Deville  in  1861.  The  name 
was  derived  from  the  village  of  Les  Beaux  in  Southern 
France  where  the  material  was  first  observed. 

Bauxite  is  never  found  in  a  crystallized  state,  but  always 
as  a  clay-like  earth.  Its  color  varies  from  light  yellow  to 

53 


ABRASIVES  AND  ABRASIVE  WHEELS 

deep  red.  The  material,  while  always  impure,  contains  a 
high  percentage  of  alumina  oxide.  Hence  its  value  as  a 
raw  material  for  the  manufacture  of  an  alumina  abrasive 
claimed  the  attention  of  abrasive  manufacturers  some 
years  ago,  when  a  substitute  for  natural  alumina  abrasives, 
that  is  to  say  emery  and  corundum,  was  seriously  given 
consideration. 

In  this  country,  bauxite  is  found  in  Georgia,  Alabama 
and  Arkansas.  In  these  localities,  the  material  in  question 
is  generally  associated. with  limestone  and  its  origin  is  at- 
tributed to  the  action  of  solutions  of  aluminum  sulphate 
on  limestone. 

CHARLES  B.  JACOBS'  PROCESS 

Mr.  Jacobs'  electric  furnace  for  carrying  out  his  process  of 
converting  bauxite  into  artificial  corundum  is  shown  in 
Fig.  6.  It  consists  of  a  rectangular  casing  (i)  with  a  slop- 
ing top,  at  the  apex  of  which  is  an  opening  (2)  which  serves 
the  double  purpose  of  charging  the  furnace  and  carrying 
off  the  volatile  matter  of  the  charge.  The  furnace  casing 
is  constructed  with  a  sheet-iron  shell  (3)  which  is  lined  with 
fire  brick  (4),  which  serves  as  a  non-conducting  material 
in  regard  to  electricity  as  well  as  heat.  Next  to  this,  are 
laid  carbon  bricks  (5). 

The  hearth  of  the  furnace  consists  of  a  cast-iron  plate 
(6)  lined  first  with  ground  lime  (7)  and  then  carbon  bricks 

(8)  laid  in  the  lime.     The  hearth  is  mounted  on  a  screw 

(9)  by  means  of  which  it  can  be  lowered  or  raised  at  will. 
By  lowering  the  hearth  during  the  furnace  run,  in  a  gradual 
manner,  a  thick  body  of  the  fused  material  is  obtained. 

Over  the  earth  are  mounted  four  pairs  of  carbon  electrodes 

(10)  between  which  the  electric  arc  is  produced.    The  fur- 
nace is  supported  by  cast-iron  legs  (n).    These  are  of  suffi- 
cient height  to  allow  the  hearth  to  be  lowered  clear  of  the 
bottom  of  the  furnace.    It  is  seen  that  the  two  outside  pairs 
of  electrodes  are  away  from  the  furnace  walls;  the  object 
being  to  keep  the  walls  clear  of  fused  material.    The  hearth 

54 


CHARLES  B.  JACOBS'  PROCESS 


Fig.  6. — Jacobs'  artificial  corundum  furnace. 
55 


ABRASIVES  AND  ABRASIVE  WHEELS 

is  left  free  to  move  up  and  down  in  the  furnace.  An 
opening  is  made  in  one  side  of  the  furnace  to  permit 
of  inspection  should  occasion  require  and  also  to  provide 
means  of  introducing  a  stirring  rod.  The  opening  is  closed 
by  the  plug  (12). 

Mr.  Jacobs'  process  of  converting  bauxite  into  artificial 
corundum  is  as  follows:  The  first  step  is  to  calcine  the  raw 
material,  the  object  of  which  is  to  drive  away  as  much 
moisture  as  possible.  This  saves  undue  expenditure  of  cur- 
rent and  wear  on  the  electrodes.  The  hearth  is  now  raised 
until  it  occupies  a  position  one  inch  below  the  electrodes, 
each  pair  of  which  is  placed  in  contact,  and  the  furnace 
filled  with  the  calcined  bauxite.'  Current  is  now  turned  on 
and  the  electrodes  pulled  apart,  causing  electric  arcs  to  be 
set  up  between  them.  The  bauxite  fuses  under  the  intense 
heat  and  the  alumina  contained  therein  runs  down  on  the 
hearth,  which  is  lowered  about  two  inches  per  hour.  This 
results  in  a  quiet  pool  of  melted  alumina  oxide  which  cools 
and  solidifies  in  crystalline  form  while  the  furnace  hearth 
descends.  During  the  process  of  fusion,  the  impurities  in 
the  raw  material  are  volatilized,  in  which  condition  they 
escape  through  the  opening  at  the  top  of  the  furnace. 

Regarding  the  temper  of  the  material,  Mr.  Jacobs  has 
the  following  to  say:  "The  nature  of  the  product  may  be 
varied  by  the  slow  or  rapid  cooling  of  the  fused  mass,  so 
as  to  obtain  a  product  of  the  same  degree  of  absolute 
hardness,  but  of  varying  toughness,  and  consequently 
varying  abrasive  power,  by  the  slow  or  rapid  lowering  of 
the  hearth.  The  more  slowly  the  product  cools,  the  better 
defined  will  be  its  crystallization  and  the  greater  its  tough- 
ness and  abrasive  power.  The  nature  of  the  product  may 
also  be  varied  by  agitating  the  mass  while  cooling,  as  by  a 
poker  or  stirring  rod  inserted  through  the  hole  normally 
closed  by  plug  12,  and  thus  disturbing  its  natural  tendency 
of  crystallization,  producing  thereby  a  finer  grain  of  crys- 
talline structure  than  when  the  material  cools  without 
disturbance." 

56 


ALUNDUM 
ALUNDUM 

Alundum  is  a  trade  name  originated  by  Norton 
Company  and  is  applied  to  an  alumina  abrasive  manufac- 
tured under  the  above-described  patent.  However,  the 
process  has  been  modified  somewhat  as  shown  by  the  fol- 
lowing account  of  the  same  by  Richard  G.  Williams,  Me- 
chanical Engineer  and  Special  Investigator  of  Norton 
Company,  in  a  paper  presented  at  the  thirty-first  general 
meeting  of  the  American  Electrochemical  Society  held  in 
Detroit,  Mich.,  May  2 — 5,  1917. 

"The  raw  material  must  necessarily  be  a  substance  high 
in  aluminum  oxide.  The  most  satisfactory  material  is  a 
high-grade  bauxite,  although  satisfactory  abrasives  are 
being  made  from  other  materials,  such  as  low-grade  bauxite 
and  emery.  Aluminous  abrasives  are  made  in  the  arc  type 
of  furnace.  These  furnaces  often  consist  of  a  wrought-iron 
shell,  or  some  form  of  pot,  lined  with  carbon.  The  electrodes 
are  suspended  in  the  pot  and  then  lowered  to  the  bottom 
of  the  furnace,  a  train  of  graphite  or  fine  coke  placed  be- 
tween the  electrodes,  the  current  turned  on  and  an  arc 
suitable  for  fusing  is  available  as  soon  as  the  train  of  graphite 
or  coke  has  volatilized. 

"Before  fusion  in  the  electric  furnace,  the  bauxite  receives 
a  calcining  treatment  to  drive  off  30  per  cent,  of  combined 
water.  Suitable  chemicals  are  mixed  with  the  calcined  ore 
in  order  to  facilitate  the  removal  of  such  materials  as  iron 
and  silicon.  Furnaces  of  three-ton  capacity  consume  between 
650  and  700  horse  power  and  it  takes  approximately  24  hours 
for  a  furnace  run.  After  the  run  is  completed,  the  shell 
is  stripped  off  or  the  furnace  sides  removed  and  the  pigs 
allowed  to  cool.  When  the  pigs  have  cooled  to  a  sufficient 
temperature,  they  are  broken  up  by  sledge  hammers  into 
pieces  convenient  for  putting  through  a  large  jaw  crusher. 
This  operation  reduces  the  material  to  pieces  about  the 
size  of  a  man's  fist,  and  in  this  condition  the  abrasive  is 
sent  to  the  grinding-wheel  factory  for  further  treatment." 

57 


ABRASIVES  AND  ABRASIVE  WHEELS 

Alundum,  as  put  on  the  market,  consists  of  two  kinds; 
ordinary  Alundum  and  white  Alundum.  White  Alundum 
makes  an  almost  white  wheel  when  bonded  by  the  silicate 
process  and  a  deep  red-colored  wheel  when  the  vitrified 
process  is  employed.  White  Alundum  is  designated  by 
the  prefix  38.  A  60  grit  wheel  made  of  white  Alundum 
is  marked  3860.  Ordinary  Alundum  is  used  for  general 
steel  grinding  on  both  rough  and  precision  work,  while 
white  Alundum  is  used  principally  for  grinding  such  ma- 
terials as  high-alloy  steels  and  general  precision  tool-room 
grinding. 

ALOXITE 

Aloxite  is  the  trade  name  of  an  alumina  abrasive  manu- 
factured by  The  Carborundum  Company.  It  is  made  from 
bauxite  in  an  electric  furnace  of  the  arc  type.  The  Car- 
borundum Company's  Aloxite  plant  is  located  at  Sarran- 
colin,  a  small  town  in  the  province  of  Hautes  Pyrenees  in 
Southern  France,  so  as  to  be  near  an  adequate  supply  of 
the  raw  material.  As  a  precautionary  measure,  however, 
several  furnaces  are  operated  at  the  Niagara  Falls  plant. 

An  Aloxite  furnace  is  quite  a  simple  affair,  consisting  of 
an  outer  shell  resting  on  a  base,  and  two  electrodes  for  sup- 
plying the  current.  The  outer  shell  is  water-cooled,  but  does 
not  have  a  refractory  lining  as  the  charge  forms  this  itself. 
It  is  placed  on  wheels  to  facilitate  moving  it  from  under 
the  electrodes  when  the  burning  operation  is  completed. 

In  charging  the  furnace,  the  bottom  is  first  lined  with  a 
mixture  of  carbon  and  tar.  Next  a  layer  of  bauxite  is  in- 
troduced and  the  electrodes  lowered  until  they  rest  on  the 
bauxite.  A  path  of  graphite  is  now  laid  between  the  elec- 
trodes, the  object  being  to  form  a  free  passage  for  the  cur- 
rent. As  soon  as  the  charge  is  in  a  molten  state,  however, 
it  forms  a  good  conductor  in  itself.  The  current  is  now 
turned  on  and  the  bauxite  brought  to  a  molten  state.  An 
alternating  current  of  6,000  amperes  at  a  pressure  of  100 
volts  is  used. 

58 


ALOXITE 


As  soon  as  the  first  layer  of  bauxite  is  in  a  molten  state, 
another  layer  is  introduced,  the  electrodes  raised,  and  this 
layer  melted.  This  process  is  continued  until  the  furnace 
is  full,  which  requires  about  thirty-six  hours.  During  the 
melting  process,  the  oxide  of  iron  and  silicon  in  the  raw 
material  unite  in  the  form  of  ferro  silicon,  thus  practically 
freeing  the  alumina  from  all  impurities.  As  a  matter  of 
fact,  Aloxite  runs  about  97  per  cent,  pure  alumina.  The 
ferro  silicon,  being  heavier  than  the  alumina,  sinks  to  the 
bottom  of  the  furnace  where  it  is  easily  disposed  of.  Several 
furnaces  are  operated  at  the  same  time,  the  object  being 
twofold;  that  is,  to  produce  a  large  supply  of  material  and 
to  keep  the  current  consumption  as  uniform  as  possible. 

After  the  furnace  has  cooled  sufficiently,  the  outer  shell 
is  removed,  exposing  the  Aloxite  ingot.  Two  of  these  are 
shown  in  Fig.  7.  The  ingots  are  first  broken  into  pieces 


Fig.  7. — Aloxite  ingots  as  they  come  from  the  furnace. 

of  about  fifty  pounds  weight  by  means  of  a  heavy  breaker 
of  the  skull-cracker  type.  The  pieces  thus  obtained  are 
next  crushed  in  an  ore  crusher  of  the  type  illustrated  in 
Fig.  8.  Two  crushers  are  employed,  the  first  one  being  set 
to  produce  lumps  about  as  large  as  a  man's  fist  while  the 
second  crusher  breaks  them  still  smaller.  The  Aloxite  lumps 
are  now  passed  through  a  magnetic  separator  which  re- 

59 


ABRASIVES  AND  ABRASIVE  WHEELS 


moves  any  lumps  of  silicon  which  may  have  clung  to  the 
ingot.  A  roller-type  crusher  is  next  used  which  completes 
the  crushing  operation.  Aloxite  is  screened  in  the  same 
manner  as  Carborundum  and  the  numbers  of  the  grades 
and  powers  are  identical. 

Aloxite  is  very  tough  and  possesses  what  might  be  termed 
a  well-regulated  temper.     The  grains  are  hard  enough  to 


I  II 


Fig.  8. — Ore  crushers  used  in  preparing  Aloxite. 

cut  rapidly,  yet  not  so  tough  that  they  will  not  fracture 
when  dull.  The  temper  of  the  grain  is  under  control,  thus 
a  uniform  abrasive  is  the  result.  In  color,  Aloxite  is  of  a 
purplish  blue  and  its  formation  is  distinctly  crystalline, 
as  Fig.  9  shows. 

Aloxite  is  adapted  for  all  kinds  of  steel  grinding,  especially 
on  precision  work  such  as  surface  grinding,  cylindrical 
grinding,  cutter  and  reamer  sharpening,  special  grinding 
operations  such  as  crank-shaft  grinding,  wherein  it  is  ab- 
solutely essential  that  the  corner  of  the  wheel  hold  a  well- 
defined  radius  for  some  time,  and  for  the  general ,  grinding 
of  high-speed  and  alloy  steels.  As  a  substitute  for  emery 
cloth,  Aloxite-coated  cloth  has  found  favor  with  many 
manufacturers  of  motor-cars  and  other  products.  Aloxite 

60 


WERLEIN'S  ARTIFICIAL  ABRASIVE 

grain  is  also  being  used  for  many  grinding  and  polishing 
operations  heretofore  done  with  emery  grain.  In  the  cut- 
glass  industry,  Aloxite  wheels  are  used  for  finishing  the 
beautiful  and  intricate  cuts  seen  on  the  best  ware,  having 


Fig-  9- — Aloxite  as  it  is  formed  in  the  furnace. 

to  a  great  extent  taken  the  place  of  the  black  Craigleith 
natural  stones  which  were  used  for  this  purpose  for  many 
years.  Aloxite  has  been  on  the  market  since  1909. 


WERLEIN'S  ARTIFICIAL  ABRASIVE 

A  comparatively  recent  patent  (French  patent  No. 
430,932,  issued  Aug.  28th,  1911)  for  the  manufacture  of  an 
artificial  abrasive  has  been  granted  to  Ivan  Werlein  of 
Seine,  France.  It  is  an  electric-furnace  product  composed 
of  alumina  and  silicon.  In  his  patent  specifications,  the 
inventor  states:  "This  alumina  and  silicon  compound 
produced  at  high  temperature  may  be  obtained  in  various 
ways.  For  instance,  a  mixture  of  80  to  95  parts  of  alumina 
and  5  to  20  parts  of  silicon  is  melted  in  an  electric  furnace. 

61 


ABRASIVES  AND  ABRASIVE   WHEELS 

When  the  mass  has  reached  about  2,888  to  3,000°  C.  it  is 
kept  at  that  temperature  for  about  20  minutes  and  then 
cooled." 

The  writer  has  never  seen  this  abrasive,  therefore  he 
is  not  in  a  position  to  comment  on  its  merits.  From  its 
composition,  however,  it  would  appear  to  have  some  of 
the  characteristics  of  Carborundum  combined  with  those 
of  the  various  alumina  abrasives.  Just  what  such  an  abrasive 
would  accomplish,  judging  from  an  American  efficiency 
standpoint,  is  a  question  of  conjecture  and  to  the  best  of 
the  writer's  knowledge,  this  abrasive  has  not  as  yet  claimed 
the  attention  of  American  abrasive  engineers. 

BORO-CARBONE 

Boro-Carbone  is  an  artificial  alumina  abrasive  made  in 
an  electric  furnace  of  the  arc  type  by  a  process  somewhat 
similar  to  that  used  in  the  manufacture  of  Aloxite  and 
Alundum.  It  contains  a  high  percentage  of  alumina  oxide 
with  a  small  amount  of  impurities.  In  color,  this  abrasive 
varies  from  a  milky  white  to  a  light  blue  and  its  crystal- 
lization is  very  pronounced. 

Boro-Carbone  is  made  in  France,  the  raw  material  being 
bauxite,  and  in  one  respect  it  enjoys  a  unique  reputation 
in  that  it  is  the  only  foreign  abrasive  that  has  been  success- 
fully able  to  compete  with  American-made  products.  To 
be  sure,  Aloxite  might  be  called  a  foreign  abrasive,  but  in 
the  strictest  sense  of  the  word,  this  is  a  fallacy,  as  it  is  a 
product  of  American  engineering  talent,  originating  at 
The  Carborundum  Company's  Niagara  Falls  plant. 

The  sale  of  Boro-Carbone  is  controlled  in  this  country 
by  the  Abrasive  Company  of  Philadelphia,  Pa.,  to  whom 
is  really  due  the  credit  of  perfecting  this  abrasive  to  a  point, 
where  it  could  compete  with  American-made  products.  It 
was  put  on  the  market  in  1912  and  at  the  present  time  en- 
joys a  large  sale,  being  adapted  for  all  kinds  of  steel  grinding. 
The  Abrasive  Company  state  that  the  temper  of  Boro- 

62 


OXALUMINA 

Carbone  can  be  varied  according  to  the  kind  of  grinding  it 
is  to  do. 

OXALUMINA 

Oxalumina  is  a  name  given  to  a  manufactured  abrasive 
of  the  artificial  alumina  type  by.  the  Cortland  Grinding 
Wheel  Corporation.  Physically,  it  is  composed  of  micro- 
scopic crystals  of  alumina;  chemically,  it  contains  about 
98  per  cent,  of  aluminum  oxide.  It  is  prepared  by  fusing 
and  refining  various  alumina-bearing  clays  and  ores  in 
carefully  regulated  furnaces.  The  resulting  mass  is  properly 
cooled,  then  crushed  and  graded  for  use  as  an  abrasive. 
This  abrasive  is  widely  advertised  and  sold  in  competition 
with  other  American  artificial  abrasives  principally  for  pre- 
cision grinding  operations. 

ADAMITE 

This  material  is  an  electric-furnace  product  made  in 
Austria.  It  contains  approximately  80  per  cent,  alumina 
oxide.  It  is  dark  blue  to  black  in  color,  being  of  a  compact, 
well  crystallized  nature.  It  is  a  very  tough  abrasive  and 
by  some  American  grinding-wheel  manufacturers  it  is  used 
to  a  limited  extent  in  the  manufacture  of  very  durable  wheels. 

ROUGE  AND  CROCUS 

Both  of  these  materials  are  made  by  the  same  process, 
which  consists  of  calcining  sulphate  of  iron  in  crystal  form. 
The  sulphate  of  iron  crystals  are  subjected  to  high  tempera- 
ture in  crucibles  and  the  powder  that  forms  at  the  bottom 
is  crocus,  while  that  at  the  top  is  rouge.  These  materials 
differ  in  color,  rouge  being  red  while  crocus  is  purple. 
These  materials  are  used  in  buffing  and  polishing  operations. 

DIAMOND  CRUSHED  STEEL 

This  material  is  manufactured  by  the  Pittsburgh  Crushed 
Steel  Company  of  Pittsburgh,  Pa.  It  is  made  of  crucible 

63 


ABRASIVES  AND  ABRASIVE  WHEELS 

steel,  subjected  to  a  special  treatment,  after  which  it  is 
crushed  and  graded  into  the  following  sizes:  4,  6,  8,  10, 
12,  14,  16,  18,  20,  30,  36,  40,  50,  60,  70,  90,  120,  150,  170,  190, 
200.  The  sizes  from  60  to  200  inclusive  are  known  to  the 
trade  as  Diamond  Steel  Emery. 

The  material  in  question  is  a  new  departure  in  abrasives; 
a  scientifically  prepared  material  designed  to  replace  emery 
for  grinding  operations  on  granite,  onyx,  marble,  brick, 
glass,  etc.,  or  in  fact  for  any  purpose  wherein  an  abrasive 
is  used  in  grain  form.  As  this  material  has  three  important 
characteristics;  hardness,  sharpness  and  toughness,  it  should 
prove  a  very  durable  grinding  agent  in  cases  where  a  rolling 
and  crushing  action  is  present. 

Crushed  steel  is  not  an  ideal  abrasive  to  employ  in  grind- 
ing-wheel  manufacture  inasmuch  as  its  tough  nature  tends 
to  prevent  the  grains  from  fracturing  upon  becoming  dull. 

ANGULAR  GRIT 

This  is  another  abrasive  material  made  by  the  above 
concern,  being  used  in  the  place  of  sand  for  sand-blasting 
operations.  It  is  a  crushed  chilled-iron  product  marketed 
in  the  following  sizes :  10,  12,  20,  30,  40,  60,  90.  This  ma- 
terial is,  without  doubt,  an  excellent  medium  to  use  for 
sand  blasting  as  the  individual  grains  have  a  number  of 
cutting  points  and  the  material  does  not  break  away,  or 
pulverize,  as  quickly  as  sand,  thus  reducing  the  objection- 
able factor  of  dust  to  a  minimum. 


CHAPTER  THREE 

THE    MANUFACTURE   OF   GRINDING   WHEELS 

Composition  of  grinding  wheels — Desirable  and  undesirable  properties — 
Bonds — Shellac — Rubber — Fusible  clays — Silicate  of  soda — Vitrified 
wheels — Method  of  producing  vitrified  wheels — Puddled  process — Pressed 
process — Silicate  wheels — Shellac  wheels — Rubber  wheels — Clay  bond 
used  in  vitrified  wheels — Choice  of  bonding  material — Wheel-turning — 
Kiln  used — Heating  of  kiln  and  work — Cooling  of  kiln — Dressing  wheels 
— Bushing  wheels — Speed  tests  for  wheels — Elastic  process — Rubber 
process. 

A  GRINDING  wheel  consists  of  two  parts — the  abrasive 
'f\  material  that  does  the  cutting  and  a  suitable  bonding 
material  to  hold  the  countless  grains  of  which  the  wheel  is 
composed  in  a  solid  mass.  Grinding  wheels  for  some  pur- 
poses, such  as  the  rough  grinding  of  heavy  gray-iron  cast- 
ings, should  be  hard  and  compact,  to  resist  undue  wear. 
A  cylinder  wheel  designed  for  a  vertical  spindle  surface 
grinding  machine,  such  as  the  Pratt  &  Whitney  Company 
manufacture,  must  be  open  and  porous  to  insure  free  cutting. 
Thus  it  is  seen  that  the  dressing  action  which  a  particular 
work  has  on  the  wheel  in  any  given  operation  must  be  given 
consideration  in  the  manufacturing  process. 

The  two  kinds  of  wheels  above  mentioned  are  at  extremes, 
but  in  the  making  of  wheels  for  various  other  purposes, 
equally  important  factors  must  not  be  overlooked.  As  an 
illustration,  wheels  for  various  tool  and  cutter  sharpening 
operations  must  be  very  cool  cutting,  while  wheels  for  such 
special  grinding  operations  as  crankshaft  finishing  are  re- 
quired to  hold  their  peripheral  shape  for  a  reasonable  length 
of  time;  otherwise  more  time  would  be  consumed  in  keep- 
ing them  in  proper  condition  than  would  be  spent  in  actual 
production. 

65 


AB^SIVES  JtfrD  ABRASIVE  WHEELS 

Some  years  ago,  when  grinding  wheels  were  used  only 
for  a  few  simple  operations  such  as  tool  sharpening  and 
general  grinding,  simple  "rule  of  thumb"  manufacturing 
methods  answered  very  well.  At  the  present  day,  however, 
owing  to  keen  competition  and  the  high  standard  required 
by  modern  efficiency  engineers,  grinding- wheel  manufac- 
ture is  fast  becoming  an  exact  science,  as  it  were,  wherein 
the  manufacturer  studies  the  requirements  of  his  customers 
and  perfects  his  production  methods  to  a  point  where  only 
the  highest  quality  of  goods  receive  the  final  inspector's 
approval. 

When  we  speak  of  the  bond  of  a  grinding  wheel,  we  refer 
to  the  material  used  to  hold  the  grains  in  the  wheel  together. 
In  the  vitrified  bond,  the  binding  medium  is  a  high  grade  of 
kaolin,  or  other  refractory  or  fusible  clays,  the  process  of 
vitrification  taking  place  in  a  kiln  patterned  after  a  pottery 
kiln.  In  the  elastic  bond,  a  good  grade  of  shellac  is  em- 
ployed, while  in  the  rubber  bond,  the  particles  of  abrasive 
material  are  held  together  by  vulcanized  rubber.  In  an- 
other process,  silicate  of  soda,  sometimes  called  waterglass, 
is  used.  All  these  bonds  possess  merit  for  specific  purposes, 
but  as  a  matter  of  fact  the  majority  of  grinding  wheels  in 
use  at  the  present  time  are  made  by  the  vitrified  process. 
This  bond  is  used  so  much  more  extensively  than  the  others 
that  it  is  possible  to  obtain  with  it  a  greater  range  of  grade 
than  is  possible  with  other  wheels.  Again,  years  of  ex- 
perience, to  say  nothing  of  costly  laboratory  experimenta- 
tion, have  proven  that  the  bond  of  a  grinding  wheel  is 
always  a  detriment  to  fast  cutting,  but  as  a  bond  of  some 
kind  is,  of  course,  a  necessity  the  one  that  will  produce 
the  least  friction  and  at  the  same  time  produce  the  desired 
grade  is  always  preferable.  Thus,  the  vitrified  bond  has 
been  found  by  practice  to  be  the  best  adapted  for  the  ma- 
jority of  purposes. 

For  the  sake  of  clearness,  all  the  above  methods  of  wheel 
manufacture  will  be  considered  separately.  The  selection 
of  correct  bonding  materials  and  the  perfection  of  the  various 

66 


THE  VITRIFIED   PROCESS 

processes  involved  is  the  result  of  many  years  of  research 
work  and  close  study  on  the  part  of  ceramic  engineers  and 
experts  on  abrasives. 

THE  VITRIFIED  PROCESS 

As  before  stated,  in  the  vitrified  process,  the  binding 
material  is  a  good  grade  of  kaolin,  or  other  refractory  or 
fusible  clay,  which  comes  to  the  grinding-wheel  manufac- 
turer in  carload  lots,  just  as  it  is  taken  from  the  earth. 
By  means  of  standardized  formulas,  the  chemist  tests  this 
material  to  make  sure  that  it  comes  up  to  a  predetermined 
standard.  Otherwise  several  thousand  finished  wheels  might 
prove  to  be  absolutely  worthless.  Further  to  test  the  value 
of  the  bonding  material,  several  small  wheels  and  briquets 
are  made  up  and  run  through  the  kilns  to  make  sure  that 
the  material  in  question  stands  a  satisfactory  heat  and 
resistance  test. 

The  foregoing  may  seem  to  the  layman  like  an  elaborate 
procedure  for  the  testing  of  a  carload  of  clay,  but  eternal 
vigilance  is  the  watchword  of  the  grinding-wheel  manufac- 
turer who  desires  to  get  new  trade  and  successfully  hold  it 
against  competition.  After  it  has  been  assured  that  the 
bonding  material  is  up  to  the  correct  standard,  it  is  care- 
fully ground  and  thoroughly  dried  and  sifted. 

The  hardness,  or  resistance  to  wear,  in  a  grinding  wheel 
is  determined  by  the  percentage  of  bond  used  with  a  cer- 
tain amount  of  abrasive  material.  A  hard  wheel  has  a 
heavy  bond,  while  in  a  soft  wheel,  the  percentage  of  bond- 
ing material  is  less.  To  adapt  an  abrasive  to  many  different 
kinds  of  work  calls  for  a  variety  of  bonds,  the  most  common 
being  the  close  tough  and  close  brittle,  open  tough  and  open 
brittle.  It  must  also  be  borne  in  mind  that  bonds  are  em- 
ployed to  produce  texture  between  these  extremes.  The 
standardization  of  grinding-wheel  bonds  is  the  result  of  many 
years  of  research  work  and  actual  experimentation.  It  is 
needless  to  state  that  bond  mixtures  are  kept  as  close  secrets. 

67 


ABRASIVES  AND  ABRASIVE  WHEELS 

In  the  manufacture  of  vitrified  grinding  wheels,  there  are 
three  methods  used  in  mixing  the  abrasive  material  with 
the  bond;  dry  mixing,  wet  mixing  and  a  combination  of 
both  these  methods.  A  dry  mixed  wheel  is  made  by  what 
is  known  as  the  pressed  process  while  a  wet  mixed  wheel  is 
made  by  the  puddled  method.  In  a  puddled  and  pressed 
wheel,  a  combination  of  both  mixing  methods  is  employed. 

In  making  wheels  by  the  pressed  process,  the  first  step 
is  to  determine  the  correct  proportions  of  grain  and  bonding 
material  by  weight,  after  which  the  mixture  is  dampened 
a  little  and  tumbled  about  in  a  tumbling  barrel  for  a  few 
hours.  The  object  of  this  procedure  is  twofold;  to  mix 
the  materials  thoroughly  and  to  surround  each  individual 
grain  of  abrasive  material  with  a  matrix  of  bonding  mixture, 
to  hold  it  in  place  in  the  finished  wheel. 

The  mixed  material  now  goes  to  the  press  room  to  be 
formed  into  wheels.  In  this  department  are  a  number  of 
hydraulic  presses,  some  of  them  capable  of  exerting  a  pres- 
sure of  5,000  pounds  per  square  inch.  The  process  of 
pressing  a  wheel  is  quite  simple  and  easily  carried  out.  An 
operator  carefully  weighs  out  the  correct  amount  of  mixture 
and  places  it  in  a  steel  mold  of  the  desired  size.  After 
leveling  the  mixture  carefully,  a  cover  that  fits  the  bore  of 
the  mold  is  placed  on  the  wheel  mixture  and  the  mold  placed 
in  position  over  the  ram  of  the  press.  With  his  eye  on  the 
pressure  gauge,  the  operator  opens  the  water  inlet  and  as 
the  ram  rises  under  the  water  pressure,  and  as  the  hand 
of  the  pressure  gauge  mounts  upward  a  crunching  sound 
is  heard  as  the  enormous  pressure  exerted  by  the  water  is 
transmitted  to  the  wheel  in  process  of  formation.  When 
just  the  exact  pressure  required  is  recorded  by  the  gauge, 
the  operator  opens  the  release,  the  ram  descends  and  the 
mold  is  removed.  The  pressed  wheel  is  now  taken  from 
the  mold,  ready  for  the  vitrifing  kiln. 

Wheels  made  by  the  pressed  process  are  very  compact 
but  not  necessarily  hard.  As  an  illustration,  a  Carborun- 
dum wheel  in  O  grade,  G2  bond  is  a  pressed  wheel,  al- 

68 


-         THE  VITRIFIED   PROCESS 

though  it  is  six  grades  softer  than  an  I  grade  wheel  in  B6 
bond,  which  is  a  puddled  wheel.  On  the  other  hand,  a 
Carborundum  wheel  in  BI6  bond,  which  is  made  by  the 
puddled  process,  is  very  hard  but  not  as  compact  as  an  I 
grade  wheel  in  G6  bond  which  is  a  pressed  wheel,  and 
although  six  grades  softer,  it  is  more  compact:  It  is  seen 
that  the  object  of  making  wheels  by  the  pressed  process  is 
to  make  them  compact,  which  characteristic  is  to  be  de- 
sired in  wheels  for  a  variety  of  grinding  purposes. 

In  making  wheels  by  the  puddled  process,  the  correct 
proportions  of  grain  and  bonding  material  are  agitated  for 
several  hours  in  mechanical  mixers  as  shown  in  Fig.  10. 


Fig.  10. — Mixing  the  materials  to  form  puddled  wheels. 

The  mixture  is  then  poured  into  a  sheet-iron  mold  and 
thoroughly  dried  by  steam  heat.  After  drying  sufficiently, 
which  consumes  several  weeks  for  very  large  wheels,  the 
embryo  wheel  is  placed  on  what  is  termed  a  shaving  machine, 
an  illustration  of  which  is  shown  in  Fig.  n.  This  machine 
is  constructed  on  the  principle  of  a  potter's  wheel,  consisting 
of  a  revolving  circular  table  upon  which  the  wheel  is  placed, 
•and  a  cross-slide  over  which  travels  the  head  carrying  the 
tools  used  in  shaping  the  wheel. 

69 


ABRASIVES  AND  ABRASIVE  WHEELS 


The  process  of  turning  the  wheel  to  the  correct  size  and 
shape,  and  boring  the  hole  for  the  lead  bushing,  is  com- 
paratively simple  although  considerable  skill  is  required  in 
turning  wheels  of  irregular  shape,  such  as  certain  wheels 
for  special  tool  grinders,  cup  wheels,  large  cylinder  wheels, 


Fig.  II. — Shaving  grinding  wheels  preparatory  to  vitrifying. 

recessed  wheels  for  cylindrical  grinding,  etc.  The  wheel- 
shaving  operator  is  a  skilled  artisan  in  his  particular  line 
of  work,  prosecuting  his  work  by  means  of  a  blue  print,  or 
other  drawing,  and  obtaining  the  necessary  dimensions  by 
means  of  scales  and  calipers  such  as  are  used  by  the  machinist. 
The  next  step  consists  of  vitrifying  the  wheels.  The 
vitrifying  kilns  used  by  grinding-wheel  manufacturers  are 
patterned  after  those  used  in  the  pottery  industry  for 
vitrifying  china  and  earthenware.  They  are  approxi- 
mately sixty -feet  high  and  sixteen  feet  in  diameter,  being 
constructed  on  what  is  called  the  down-draft  principle. 
A  secondary  interior  wall  is  built  inside  the  kiln,  coming  to  a 

70 


THE  VITRIFIED   PROCESS 

crown  about  twenty  feet  from  the  kiln  floor.  The  heat  is 
so  distributed  that  it  circulates  freely  in  all  parts  of  the 
kiln  interior,  finding  an  outlet  at  the  bottom. 

The  wheels,  as  they  come  from  the  press  and  puddling 
rooms,  are  placed  in  earthenware  receptacles  technically 
termed  sagers,  a  few  of  which  are  shown  at  the  left-side 
foreground  of  Fig.  12.  As  the  wheels  are  in  what  is  termed 


Fig.  12. — Loading  a  grinding- wheel  kiln. 

a  "green"  state,  care  is  necessary  in  handling  them.  To 
insure  even  bedding  in  the  sagers,  the  wheels  are  placed  on 
a  layer  of  sand.  Several  small  wheels  are  loaded  in  one 
sager  but  with  medium-sized  wheels,  say  12x2,  one  to  a 
sager  is  considered  sufficient.  Wheels  14  inches  in  diameter 
and  over  are  piled  one  over  the  other  in  sectional  sagers, 
each  wheel  being  bedded  in  sand. 

An  interior  view  of  a  grinding-wheel  kiln  is  shown  in 
Fig.  13,  wherein  several  piles  of  sagers  are  shown  in  the 
background.  After  the  kiln  is  completely  filled,  the  door 
is  sealed  tight  and  the  kiln  is  ready  for  firing.  To  correctly 
burn  a  kiln  of  grinding  wheels  is  an  operation  calling  for 
long  practice.  It  consists  of  bringing  the  kiln  up  to  the 
correct  heat,  keeping  it  there  for  the  necessary  period  and 

71 


ABRASIVES  AND  ABRASIVE  WHEELS 

then  letting  it  cool  gradually.  Too  much  heat  would  result 
in  over-burning,  the  effect  being  the  destruction  of  the  bond, 
leaving  it  in  a  burnt-up  or  honeycombed  condition,  while  too 
little  heat  would  produce  an  under- vitrified  wheel.  Again, 
if  the  kiln  is  brought  up  to  full  heat  too  rapidly,  wheels 


Fig.  13. — Interior  of  a  grinding- wheel  kiln. 

having  hard  and  soft  spots  are  liable  to  result.  Further, 
if  the  kiln  is  allowed  to  cool  too  rapidly  75  per  cent,  of  its 
contents  will  come  out  in  a  cracked  state,  being  absolutely 
of  no  value,  for,  unlike  the  good  housewife's  pie-crust, 
grinding  wheels  cannot  be  worked  over  again. 

Arranged  around  the  base  of  the  kiln,  are  approximately 
ten  fire  boxes,  the  fuel  used  being  a  good  grade  of  either 
anthracite  or  bituminous  coal.  Two  fires  are  started  at  a 
time  and  allowed  to  burn  for  some  time,  after  which  two 
more  are  started  at  regular  intervals  until  all  are  burnr'ng. 
The  kiln  is  now  brought  up  to  the  first,  or  red  heat,  which 
takes  fifteen  hours.  The  heat  is  gradually  increased  until 
the  kiln  is  at  what  is  termed  the  "low  melting  point." 
Tests  are  frequently  made  by  means  of  sets  of  pyrometric 
cones  which,  are  inserted  in  the  kiln  through  test  holes. 
There  are  several  of  these  test  holes  in  every  kiln  arranged 
at  regular  intervals  and  it  is  important  that  the  readings  of 
each  test  hole  tally,  otherwise  it  is  a  sign  that  the  heating  is 
uneven.  The  test  cones  are  made  of  clays  having  different 
melting  points.  Three  cones  having  different  melting  tem- 
peratures are  placed  on  one  base.  When  the  first  one  melts 
°nd  topples  over,  it  is  a  sign  that  the  kiln  is  at  "red  heat." 

72 


THE  VITRIFIED   PROCESS 

The  next  one  succumbs  at  low  melting  point  and  when  the 
third  one  wilts  under  the  heat,  it  signifies  that  the  kiln  is 
up  to  full  heat  or  a  trifle  higher  than  2,500°  Fahr.  A  set  of 
the  cones  used  is  illustrated  in  Fig.  14.  For  many  years,  the 
pyrometrical  cone  was  the  only  means  used  for  determining 
the  heat  of  the  kiln.  Of  late  years,  however,  owing  to  the 


Fig.  14. — Pyrometric  cones  used  for  measuring  degree  of  temperature  in 
grinding-wheel  kilns. 


high  degree  of  perfection  reached  in  the  manufacture  of 
various  types  of  pyrometers  for  accurately  determining  high 
temperatures,  the  latter  are  now  used  in  connection  with  the 
former  in  grinding-wheel  kiln  burning. 

After  the  kiln  has  reached  full  heat,  it  is  sealed  up  and 
allowed  to  cool  for  several  days.  As  much  care  has  to  be 
exercised  in  cooling  the  kiln  as  in  heating  it,  for  sudden  or 
uneven  cooling  would  bring  about  disastrous  results  to  the 
contents.  It  takes  three  days  to  load  a  kiln,  five  days  to 
burn  it,  a  week  is  allowed  for  cooling  and  three  days  for 
unloading.  Small  wonder,  then,  that  the  grinding-wheel 
manufacturer  cannot  ship  special  wheels  a  few  days  after 
the  order  for  the  same  has  been  entered.  Burning  a  kiln  of 
grinding  wheels  is  an  operation  that  cannot  be  carried  on 
too  carefully,  as  a  slight  error  in  judgment  is  sufficient  to 
turn  success  into  failure.  The  men  who  have  charge  of  this 
important  work  become  skilled  through  long  experience,  and 
it  is  needless  to  state  that  they  are  numbered  among  the 
grinding-wheel  manufacturer's  trusted  employees. 

From  the  kilns,  the  grinding  wheels  go  to  the  sorting  room 
73 


ABRASIVES  AND  ABRASIVE  WHEELS 

where  they  are  sorted  according  to  size,  grit  and  grade. 
The  grits  and  grades  are  determined  by  markings  scratched 
on  the  wheels  while  in  the  "green"  state,  before  vitrifying. 
The  wheels  are  next  inspected  for  soundness  by  tapping  them 
with  a  light  hammer.  A  sound  wheel  will  emit  a  faint,  bell- 
like  tone  when  tapped,  this  tone  having  a  distinct  reverbera- 
tion, whereas  a  cracked  wheel  gives  out  a  dead  sound  in 
which  no  reverberation  is  detected. 

The  wheels  that  pass  this  inspection  go  to  the  lathe  room, 
where  they  are  faced  and  edged.  The  type  of  lathe  used 
for  facing  is  not  unlike  an  ordinary  engine  lathe  with  the 
possible  exception  that  the  former  is  slightly  heavier  than 
the  latter.  The  wheel  is  firmly  gripped  in  a  universal  chuck 
and  a  cut  taken  over  one  side,  bringing  the  surface  as  near 
to  a  true  plane  as  possible  within  practical  limits.  The 
wheel  is  now  reversed  in  the  chuck  and  the  other  side  faced, 
care  being  exercised  to  make  sure  that  the  sides  are  parallel ; 
otherwise  the  wheel  might  be  out  of  balance,  which  feature 
is  to  be  avoided. 

For  facing  large  wheels,  star-toothed  dressers  of  the  type 
familiar  to  every  mechanic  are  used.  These  are  mounted 
in  suitable  holders  which  are  gripped  in  the  tool  post.  For 
fine,  comparatively  small  wheels,  diamonds  mounted  in 
copper  bars  are  used.  Being  in  constant  use,  these  stones 
soon  wear  out;  thus  the  diamond  bill  of  the  grinding- 
wheel  manufacturer  amounts  to  a  large  sum  annually. 

After  being  faced,  the  wheels  are  ready  for  the  first  in- 
spection for  grade.  This  operation  is  done  by  hand  as 
shown  in  Fig.  15.  The  instrument  used  looks  not  unlike 
a  short,  wide  screw-driver  mounted  in  a  heavy  handle.  To 
determine  the  grade,  the  operator  depends  wholly  on  his 
senses  of  hearing  and  touch,  which,  through  constant  prac- 
tice, are  very  reliable.  The  testing  is  done  simply  by 
gouging  into  the  wheel  in  several  places,  noting  the  sound 
given  out  and  feeling  the  amount  of  resistance  met  in  separat- 
ing the  particles  of  abrasive  from  the  bond. 

Constant  practice  makes  these  operators  very  expert, 
74 


THE  VITRIFIED   PROCESS 

especially  in  grading  medium  hard,  medium  and  medium 
soft  wheels.  With  the  very  hard  wheels,  however,  it  is 
almost  impossible  to  make  an  impression  with  the  grading 
tool.  In  this  case,  the  operator  relies  almost  wholly  upon 
the  sound  emitted.  Several  mechanical  means  have  been 


Fig.  15. — Grading  grinding  wheels  by  the  hand-test  method. 

devised  for  grading  grinding  wheels,  but  as  yet  not  one  has 
been  perfected  that  is  as  reliable  as  the  simple  hand-grading 
tool  in  the  hands  of  an  expert. 

The  next  step  is  to  provide  the  wheels  with  lead  bushings. 
In  this  operation,  the  wheel  is  held  in  a  special  fixture  which 
locates  it  centrally.  A  mandrel  of  the  desired  size  is  now 
inserted  and  the  space  between  the  mandrel  and  the  grind- 
ing-wheel  hole  filled  with  molten  lead.  As  soon  as  the  lead 
cools  sufficiently,  the  bushing  is  stamped  with  the  grit  and 
grade,  and,  in  the  case  of  Carborundum  wheels,  the  bond 
also,  as  a  means  of  permanent  identification.  This  practice 
originated  with  The  Carborundum  Company,  and  it  is  need- 
less to  state  that  it  fills  a  long-felt  want  as  the  consumer 
has  at  hand  a  reliable  guide  in  duplicating  a  successful 
wheel. 

75 


ABRASIVES  AND  ABRASIVE  WHEELS 

The  next  operation  is  to  true  the  periphery  of  the  wheel. 
This  is  done  by  men  called  wheel  edgers.  The  wheels  are 
mounted  on  heavy  grinding  stands  and  the  edging  done  by 
means  of  star-shaped  dressers  fed  by  hand.  Diamonds 
are  used  on  the  smaller  and  more  delicate  wheels.  The 
grinding-wheel  stands  are  equipped  with  guards  to  eliminate 
danger  from  flying  fragments  in  case  a  wheel  should  hap- 
pen to  burst,  and  the  workman's  health  is  also  taken  into 
consideration  as  an  efficient  exhaust  system  is  provided  to 
carry  away  the  dust. 

The  wheels  are  now  ready  for  another  important  oper- 
ation, that  of  balancing.  Owing  to  the  high  speed  at  which 
they  are  operated,  it  is  very  necessary  for  grinding  wheels 
to  be  in  almost  perfect  running  balance.  Carefully  worked- 
out  tables,  prepared  by  the  engineering  department,  show 
the  exact  amount  any  size  of  wheel  can  be  out  of  balance, 
and  all  wheels  failing  to  come  up  to  this  predetermined 
standard  are  rejected. 

The  balancing  is  done  by  mounting  the  wheel  on  an  arbor 
which  is  placed  on  balancing  ways.  If  a  heavy  side  is  in 
evidence,  a  weight  of  the  required  number  of  ounces  allowed 
on  this  particular  size  of  wheel  is  clamped  on  the  periphery 
opposite  the  heavy  side.  If  this  weight  fails  to  counter- 
balance the  wheel,  it  shows  that  the  wheel  is  out  of  balance 
to  the  extent  of  warranting  rejection  for  the  particular 
size  in  question,  although  it  can  be  turned  smaller  when, 
in  all  probability,  it  will  pass  a  satisfactory  test.  It  is  very 
necessary  that  the  balance  of  wheels  intended  for  precision 
grinding  be  almost  perfect ;  otherwise  accurate  work  on  the 
part  of  the  grinding-machine  operator  is  sometimes  im- 
possible. 

Owing  to  the  fact  that  grinding  wheels  are  used  under 
various  conditions,  some  of  which  are  far  from  ideal, 
chances  for  serious  accidents  owing  to  the  bursting  of  the 
wheel  must  be  guarded  against  by  the  manufacturer  who 
aims  to  market  reliable  goods.  To  this  end,  grinding  wheels 
are  given  a  speed  test  before  going  to  the  shipping-room. 

76 


THE  VITRIFIED  PROCESS 

As  the  centrifugal  force  of  a  body  moving  with  different 
velocities  in  the  same  circle  is  proportional  to  the  square 
of  the  velocity,  it  is  evident  that  if  the  velocity  is  doubled 
the  centrifugal  force  will  be  four  times  as  great.  Thus  it 
is  seen  that  if  a  wheel  is  speeded  fifty  per  cent,  faster  than 
the  recommended  operating  speed,  the  centrifugal  force 
would  be  twice  as  great.  The  Carborundum  Company 
make  a  practice  of  speeding  all  wheels  above  eight  inches 
in  diameter  seventy  per  cent,  higher  than  the  recommended 
operating  speed.  After  this  test,  it  is  safe  to  assume  that 
the  wheel  is  sound  and  when  used  under  the  proper  oper- 
ating conditions  the  danger  of  breakage  is  practically  nil. 

The  speed-testing  machines  consist  of  substantial  grinding- 
wheel  stands  equipped  with  variable-speed  counter-shafts 
for  increasing  and  decreasing  the  speed  as  desired,  accurate 
tachometers  for  registering  the  number  of  revolutions,  and 
stout,  iron-bound  oak  boxes  surrounding  the  wheels  to 
retain  the  fragments  in  case  a  wheel  fails  to  withstand  the 
speed  test.  Two  testing  machines  are  shown  in  Fig.  16. 
The  tests  are  conducted  in  a  very  deliberate  manner  by 
men  whose  integrity  can  be  depended  upon  and  at  the  com- 
pletion of  each  day's  work  these  men  subscribe  and  swear 
before  a  notary  public  to  the  tests  they  have  made.  The 
number  and  conditions  of  each  test  are  kept  in  a  book  pro- 
vided for  this  purpose  and  a  certificate  is  attached  to  the 
tested  wheel,  showing  both  the  test  speed  and  the  recom- 
mended operating  speed. 

Accidents  caused  by  grinding-wheel  imperfections  are 
indeed  very  rare.  The  writer  has  personally  investigated 
many  cases  of  broken  grinding  wheels  and  has  yet  to  find 
a  case  where  the  accident  was  caused  directly  by  imper- 
fections in  the  manufacture  of  the  wheel.  That  all  grinding- 
wheel  manufacturers  intend  to  market  dependable  wheels  is 
borne  out  by  the  following  paragraph  taken  verbatim  from 
The  Carborundum  Company's  Number  Five  catalogue. 

"In  May,  1902,  the  Association  of  German  Engineers 
began  an  exhaustive  series  of  speed  tests  of  abrasive  wheels. 

77 


ABRASIVES  AND  ABRASIVE  WHEELS 

These  tests  were  conducted  by  Professor  Griiber  of  the 
Technical  High  School,  Dresden.  All  manufacturers  were 
invited  to  submit  a  2o-inch  wheel  to  be  speeded  until  it 
burst.  About  sixty  wheels,  including  almost  all  standard 
makes,  were  tested  in  this  manner.  The  result,  as  a  whole, 


Fig.  1 6. — Speed-testing  grinding  wheels  for  safety. 

demonstrated  the  entire  safety  of  all  makes  of  wheels  when 
properly  used;  for,  while  the  proper  operating  speed  for  a 
2o-inch  wheel  is  955  revolutions  per  minute,  the  poorest 
record  made  by  any  wheel  tested  was  2,615  revolutions 
per  minute  before  bursting.  The  regular  grade  of  Car- 
borundum wheel  tested  made  4,340  revolutions  per  minute 
before  bursting,  which  was  the  best  record  made  by  any 
wheel  tested." 

The  above  statements  bear  out  the  writer's  opinion,  i.  c., 
73 


THE   SILICATE   PROCESS 

that  the  specific  gravity  of  Carborundum,  being  less  than 
that  of  other  abrasives,  makes  it  a  very  efficient  and  safe 
wheel. 

THE  SILICATE  PROCESS 

In  making  wheels  by  the  silicate  process,  silicate  of  soda 
and  the  abrasive  material  are  first  mixed  together  in  the 
proper  proportions  in  mechanical  mixers.  This  mixture  is 
then  tamped  by  hand  in  iron  molds.  The  operation  of 
tamping  the  mixture  calls  for  a  high  degree  of  skill,  thus 
the  work  can  only  be  intrusted  to  experienced  men.  Ma- 
chines have  been  devised  for  tamping  silicate  wheels,  but 
the  mechanical  process  does  not  produce  as  satisfactory 
results  as  are  obtained  with  the  hand-tamping  process. 
Why  this  is  so  is  a  matter  of  conjecture.  Nevertheless,  the 
fact  remains  that  hand-tamped  wheels  are  turned  out  in 
large  lots  daily  by  grinding- wheel  manufacturers. 

On  first  thought,  it  would  appear  that  silicate  wheels 
could  be  readily  pressed  in  molds  by  the  same  process  used 
in  making  pressed  vitrified  wheels  as  heretofore  explained. 
This  method  has  been  the  basis  of  lengthy  experiments 
without  tangible  results,  the  product  always  showing  in- 
ferior in  actual  tests. 

The  process  of  hand  tamping  is  comparatively  slow  and 
laborious  as  it  has  to  be  done  in  a  thorough  manner,  but  when 
properly  carried  out  excellent  wheels  are  the  result.  After 
tamping,  the  wheels  are  baked  slightly  under  low  heat, 
which  sets  the  bond.  For  many  years  it  was  considered  an 
impossibility  to  make  Carborundum  wheels  by  the  silicate 
process,  inasmuch  as  the  glassy  nature  of  this  abrasive 
and  the  same  characteristic  in  the  bonding  material,  after 
baking,  did  not  form  a  good  contact.  Of  late  years,  how- 
ever, this  difficulty  has  been  overcome. 

Silicate  wheels  are  very  close  in  texture  and  they  are 
successfully  used  on  grinding  operations  where  a  compact, 
but  at  the  same  time  a  comparatively  free  cutting  wheel 
is  desired.  For  tool  grinding  in  the  machine  shop,  saw 

79 


ABRASIVES  AND  ABRASIVE  WHEELS 

gumming  and  knife  grinding  in  wood-working  establish- 
ments and  on  other  operations  of  like  nature,  silicate  wheels 
are  successfully  used.  Again,  the  silicate  process  is  exten- 
sively used  by  small  grinding-wheel  manufacturers  who 
have  not  the  facilities  for  turning  out  vitrified  wheels  in 
large  lots.  Further,  an  inferior  abrasive,  one  containing 
an  excess  of  mica  or  garnet,  for  instance,  can  be  used  in 
the  manufacture  of  silicate  wheels,  whereas  these  impuri- 
ties would  ruin  a  vitrified  wheel.  Inasmuch  as  the  silicate 
process  is  of  short  duration,  hurry  orders  for  grinding  wheels 
can  be  filled  in  far  less  time  than  is  required  to  make  them 
by  the  vitrified  process.  This  factor  is,  of  course,  worth 
consideration  in  a  few  specific  cases. 

In  the  early  days  of  the  grinding-wheel  industry,  the 
silicate  process  was  quite  popular  owing  to  the  fact  that 
wire-web  wheels,  wherein  a  screen  of  brass  wire  was  in- 
serted, were  considered  as  an  ample  safeguard  against 
accidents.  At  the  present  day,  however,  owing  to  the 
high  development  of  the  vitrified  process  and  the  subse- 
quent safety  of  the  finished  product,  there  is  no  logical 
excuse  for  using  silicate  wheels  purely  as  a  matter  of  safety. 

THE  ELASTIC  PROCESS 

In  making  wheels  by  the  elastic  process,  wherein  the 
binding  medium  is  shellac,  the  first  step  is  to  melt  the  shel- 
lac, which  is  afterward  cooled  and  broken  into  lumps. 
The  lumps  are  next  finely  ground  and  the  proper  propor- 
tions of  shellac  and  abrasive  mixed  together.  This  mixture 
is  then  transferred  to  a  hot  mold  and  thoroughly  melted 
under  pressure.  A  slight  baking  in  specially  constructed 
ovens  completes  the  process. 

Shellac -bonded  wheels  are  very  cool  cutting,  imparting 
a  high  degree  of  finish  to  the  work,  and,  owing  to  the  firm 
nature  of  the  bonding  material,  they  are  the  safest  form  of 
wheel  to  use  for  any  purpose.  This  bond  is  especially  de- 
sirable for  comparatively  thin  wheels  as  used  for  grinding 

80 


THE   RUBBER   PROCESS 

out  slots,  fine  saw  gumming,  marble  coping,  etc.  Small, 
delicate  cup  and  dish  wheels,  as  used  for  certain  kinds  of 
cutter  sharpening  in  the  machine  shop,  are  generally  made 
by  the  shellac  process.  For  the  finish  grinding  of  the  large 
calender  rolls  used  in  paper  making,  the  shellac  bond  is  the 
accepted  favorite,  owing  to  the  high  degree  of  finish  im- 
parted. Hones  of  various  shapes  used  in  polishing  marble 
are  also  made  by  this  process. 

The  layman  is  inclined  to  associate  shellac  with  the 
sticky  variety  used  in  liquid  form'  by  the  pattern  maker 
and  other  wood  workers  and  therefore  is  sometimes  in- 
clined to  think  that  a  grinding  wheel  bonded  with  this 
material  would  soon  fill  up,  and  consequently  refuse  to  cut. 
Actual  tests,  however,  have  proven  beyond  all  doubt  that 
the  shellac-bonded  grinding  wheel  is  very  free  cutting; 
probably  owing  to  the  fact  that  the  heat  used  in  baking 
brings  about  a  chemical  change  in  the  bond  which  elimin- 
ates the  tendency  of  the  material  to  retain  the  minute 
particles  removed  from  the  work  by  the  action  of  abrasion. 

THE  RUBBER  PROCESS 

In  cases  where  grinding  wheels  are  subjected  to  very  severe 
strains,  especially  when  very  thin  wheels  are  used,  the 
rubber  process  makes  a  very  satisfactory  wheel.  Many 
years  ago,  before  the  present-day  state  of  perfection  in 
grinding-wheel  manufacture,  large  wheels  were  made  by 
the  rubber  process,  and  in  a  very  few  cases,  there  is  a  demand 
for  these  wheels  at  the  present  time.  The  majority  of 
rubber  wheels  used  today,  however,  are  comparatively  thin 
ones  used  for  such  purposes  as  grinding  slots  in  cast-iron 
stove  doors,  sawing  stone,  etc.,  or  in  fact  for  any  operation 
where  an  exceedingly  durable  wheel  is  desired. 

The  process  of  making  rubber  bonded  wheels  is  quite 
simple,  consisting  of  passing  carefully  selected  crude  rubber 
and  abrasive  material  between  steam-heated  chilled  iron 
rolls.  The  material  is  passed  and  re-passed  until  all  the 

81 


ABRASIVES  AND  ABRASIVE  WHEELS 

abrasive  material  is  thoroughly  imbedded  in  the  rubber. 
When  the  required  amount  of  material  is  worked  up,  the 
Operator  scribes  a  circle  of  the  desired  diameter  on  the 
sheet  of  material  with  a  pair  of  dividers,  cuts  the  outline 
thus  made  with  a  sharp  knife,  punches  a  hole  in  the  center 
of  the  disc  and  the  wheel  is  ready  for  the  final  process,  that 
is  vulcanizing  the  rubber.  This  is  done  in  a  small  furnace, 
electrically  heated,  and  takes  but  a  short  time 


CHAPTER  FOUR 

ARTIFICIAL   SHARPENING   STONES 

Properties  of  artificial  stones — Carborundum  stones — Method  of  manufac- 
ture— Bond — Grit — Grade — Finishing — Combination  stone^-Carboran- 
dum  rubs. 


to.  01   mar 
i&s— Carb 

" 


ARTIFICIAL  sharpening  stones  have  been  on  the  mar- 
ket for  many  years,  dating  from  the  time  when  the 
early  grinding-wheel  manufacturers  put  them  on  the  market 
in  small  lots.  It  is  a  fact  that  when  any  abrasive  material 
is  crushed,  much  of  the  same  is  reduced  to  a  fine  powder, 
which  is  of  no  value  in  the  manufacture  of  grinding  wheels. 
Thus,  one  reason  for  the  introduction  of  artificial  "sharpening 
stones  in  competition  with  the  natural  product  was  that  the 
grinding  wheel  and  abrasive  manufacturer  sought  a  market 
for  the  fine  grains  that  otherwise  have  but  little  market 
value. 

Artificial  sharpening  stones  possess  one  merit  that  should 
not  be  undervalued,  in  that  they  are  generally  very  uniform 
in  grit  and  grade.  Absence  of  hard  and  soft  spots  is  an- 
other good  characteristic  which  is  not  always  present  in 
natural  stones.  Any  good  abrasive  material  can  be  made 
into  sharpening  stones,  but  the  artificial  abrasives  seem  to 
hold  the  preference,  owing  to  their  purity  and  uniformity  as 
compared  to  natural  abrasives. 

The  first  artificial  abrasive  to  be  put.  on  the  market  in  the 
form  of  sharpening  stones  was  Carborundum.  During  the 
last  few  years,  the  demand  for  these  stones  has  advanced 
by  leaps  and  bounds,  so  to  speak,  two  reasons  being  assigned 
for  this.  First,  they  are  carefully  made  by  skilled  workmen, 
which  procedure  always  results  in  a  superior  product,  and, 

83 


ABRASIVES  AND  ABRASIVE  WHEELS 

again,  they  are  universally  advertised,  being  on  sale  in 
every  town  and  city  throughout  the  civilized  world.  Over 
a  million  and  a  quarter  of  Carborundum  sharpening  stones 
are  sold  annually  in  more  than  one  hundred  and  fifty  dif- 
ferent sizes,  styles,  etc. 

Carborundum  sharpening  stones  are  made  in  vitrified 
bond  by  the  pressed  process,  the  principle  being  the  same 


Fig. -1 7. — Finishing  Carborundum  sharpening  stones  on  rotary  laps. 

as  employed  in  making  pressed  wheels,  with  the  exception 
that  the  work  is  carried  on  on  a  smaller  scale.  Great  care  is 
exercised  in  molding  the  stones.  Careful  workmen  deter- 
mine the  amount  of  grain  and  bond  mixture  by  weight; 
thus,  exactly  the  same  amount  of  material  is  incorporated 
into  all  stones  of  a  given  size.  This  material  is  evenly  dis- 
tributed in  the  mold,  otherwise  the  finished  stone  would 
have  what  is  technically  termed  "heavy  spots."  Again, 
the  amount  of  pressure  exerted  on  the  mixture  after  the 
mold  is  placed  in  position  in  the  hydraulic  press  must  be 

84 


ARTIFICIAL  SHARPENING  STONES 

watched  carefully,  otherwise  the  finished  product  would 
vary  in  grade.  As  the  stones  are  very  delicate  in  the 
"green"  state,  and  thus  easily  damaged,  it  is  necessary  to 
handle  them  carefully.  They  are  loaded  ;n  sagers  and 
vitrified  by  the  same  process  and  in  the  same  kilns  used 
in  the  manufacture  of  vitrified  Carborundum  wheels. 
Carborundum  sharpening  stones  are  made  in  three  grits, 


Fig.  1 8. — Part  of  the  specialty  department  at  The  Carborundum  Company's 

plant. 

namely,  coarse,  medium  and  fine.  The  coarsest  grain  is 
used  in  number  120,  while  number  180  is  used  in  medium 
stones.  Fine  stones  are  made  in  F,  FF,  and  FFF  powders. 
A  superfine  powder  called  6o-minute  powder  (so  called 
because  it  takes  60  minutes  to  settle  in  water)  is  used  in 
making  several  very  fine  stones. 

Large  flat  stones  are  made  in  G— 7  bond  for  fine  grits  and 
in  G-5  bond  for  coarse  grits.  For  other  stones,  points, 
sticks,  etc.,  G-i2  bond  is  used.  For  making  razor  hones 
and  other  fine  instrument  stones  a  special  bond  is  used  to 
give  the  desired  hardness,  the  nature  of  this  bond  being 
a  trade  secret. 

85 


ABRASIVES  AND  ABRASIVE  WHEELS 

In  making  combination  stones,  that  is,  stones  composed  of 
two  grits,  fine  on  one  side  and  coarse  on  the  other,  two 
methods  are  used.  One  method  is  to  level  the  fine  mixture 
in  the  mold  and  over  this  place  the  coarse  mixture,  both 
being  pressed  together.  The  other  method  consists  of 
cementing  two  finished  stones,  a  coarse  one  and  a  fine  one, 
together. 

After  the  stones  come  from  the  vitrifying  kilns,  they  are 


Fig.  19. — A  few  varieties  of  Carborundum  sharpening  stones. 

carefully  inspected  for  imperfections  such  as  cracks,  burned 
spots,  etc.,  arid  all  imperfect  specimens  thrown  aside.  The 
stones  which  pass  this  inspection  go  to  the  finishing  de- 
partment, where  skilled  artisans  rub  them  smooth  on  hori- 
zontal rubbing  beds,  or  rotary  laps.  The  abrasive  used 
in  tliis  operation  is  Carborundum  grain  mixed  with  water. 
This  operation  is  shown  in  Fig.  17. 

The  stones  are  now  transferred  to  the  specialty  depart- 
ment, where  they  are  carefully  buffed,  cleaned,  inspected 
and  packed  in  boxes  and  display  cases.  A  view  of  this 
department  is  shown  in  Fig.  18.  As  before  stated,  Car- 
borundum sharpening  stones  are  made  in  upwards  of  one 
hundred  and  fifty  different  styles,  being  used  for  a  diversity 
of  purposes  too  numerous  to  mention  here.  Some  of  the 
well-known  varieties  are  shown  in  Fig.  19. 

A  form  of  stone  technically  called  a  "rub"  is  much  used 
for  smoothing  castings,  marble,  granite,  cement,  etc.  These 
are  made  in  the  same  manner  as  sharpening  stones,  with 
the  exception  that  the  grits  are  coarser  and  no  extra  finish 
is  imparted  after  they  come  from  the  vitrifying  kilns. 

86 


ARTIFICIAL  SHARPENING  STONES 

Considerable  skill  has  been  developed  in  the  manufacture 
of  Carborundum  sharpening  stones 'and  rubs,  through  the 
study  of  proper  bonding  materials,  methods  of  manufac- 
ture, etc.,  thus  the  finished  products  are  very  uniform  and 
do  not  vary  to  any  noticeable  extent. 


CHAPTER    FIVE 

GRITS  AND   GRADES 

Designation  of  grits  and  grades — Mixed  grits— ^rits  of  abrasive  papers- 
Standard  grades — Wheels — Relation  of  speed  to  grade  and  grit — Wheel 
speeds  for  various  operations. 

THE  grit,  or  grain  as  it  is  sometimes  called,  of  a  grinding 
wheel  alludes  to  the  size  of  the  particles  of  abrasive 
material  of  which  it  is  composed.  Thus,  a  wheel  in  24  grit 
is  made  up  of  particles  of  abrasive  material  that  were 
separated  from  the  mass  that  passed  over  the  grading  ma- 
chine by  a  screen  having  24  meshes  to  the  linear  inch. 
It  is  sometimes  erroneously  stated  that  the  particles  of 
grit  composing  a  24-grain  grinding  wheel  are  1/24  inch  in 
diameter.  This  is  not  true,  because  the  size  of  the  wire  of 
which  the  screen  is  made  must  be  taken  into  consideration. 
Therefore,  if  the  screen  was  made  of  very  coarse  wire, 
the  particles  of  grit  passing  through  it  would  be  somewhat 
finer  than  those  passing  through  a  screen  having  the  same 
number  of  meshes  per  inch  but  made  of  finer  wire. 

Grinding-wheel  grits  are  referred  to  as  straight,  mixed, 
combination  and  combination  mixed.  A  straight  grit  is 
one  wherein  the  abrasive  is  of  one  size  only;  thus  if  40  grit 
was  used  the  wheel  would  be  a  40  straight  grit.  For  con- 
venience, the  word  ''straight"  is  generally  omitted  in 
speaking  of  a  straight  grit  wheel.  When  a  40  grit  wheel  is 
ordered,  it  is  understood  that  a  straight  grit  is  required. 

A  mixed  grit  is  one  composed  of  two  or  three  different 
kinds  of  abrasive  materials.  Thus,  a  wheel  designed  for 
grinding  steel  castings,  for  an  illustration,  made  of  a  mix- 
ture of  emery,  corundum  and  adamite,  would  be  a  mixed- 
grit  wheel. 

88 


GRITS  AND  GRADES 

By  a  combination  grit,  which  term  is  sometimes  errone- 
ously used  to  designate  a  mixed  grit,  is  meant  a  combina- 
tion of  various-sized  grits,  scientifically  selected,  and  in- 
corporated into  one  wheel.  A  combination  mixed  grit  is 
one  wherein  two  or  more  abrasives  are  used,  the  grains 
being  of  different  sizes. 

A  wheel  composed  of  a  combination  of  24,  36  and  80 
grit  is  known  as  a  24-combination  grit.  Successful  grit 
combinations  are  standardized  only  through  long  experi- 
ment and  actual  tests,  and  the  grin  ding-wheel  manufacturer 
generally  keeps  them  secret.  The  Norton  Company  make 
many  combination  grits,  referring  to  them  simply  as  24 
combination,  36  combination,  etc.  The  Carborundum  Com- 
pany, who  have  investigated  the  theory  and  practical 
results  derived  from  combination  grits  in  a  very  thorough 
manner,  have  originated  a  simple  means  for  designating 
their  grit  combinations,  which  is  of  great  benefit  to  the  cus- 
'tomer  in  re-ordering.  They  use  a  number  of  grit  combina- 
tions designated  i,  2,  3,  4,  etc.  This  number  is  annexed 
to  the  grit  number,  thus  a  365  combination  grit  has  36 
grain  for  its  base  while  5  stands  for  the  combination  number. 

For  certain  operations,  combination  grits  offer  decided 
advantages.  On  cylindrical  grinding,  for  instance,  a  wheel 
in  a  combination  grit  with  a  comparatively  coarse  base, 
24  to  36,  cuts  very  fast  and  at  the  same  time  leaves  a  smooth 
finish,  leading  to  the  deduction  that  the  coarse  grains 
remove  material  rapidly,  while  the  finer  grains  impart  the 
desired  finish.  On  certain  operations  where  a  very  durable 
wheel  is  required,  on  car-wheel  grinding,  for  example,  a 
combination  grit  gives  entire .  satisfaction,  showing  high 
efficiency  over  a  straight  grit  used  for  the  same  purpose. 

Manufacturers  of  abrasive  paper  and  cloth  designate  the 
different  grits  by  numbers:  i,  1-1/2,  2,  2-1/2,  etc.  At  one 
time,  the  various  grits  used  by  different  manufacturers 
varied  to  quite  an  extent  even  though  they  were  designated 
by  the  same  number.  This  often  led  to  confusion  and  some- 
times enabled  one  manufacturer  to  gain  an  unfair  ad- 

89 


ABRASIVES  AND  ABRASIVE  WHEELS 

vantage  over  another.  For  instance,  a  certain  manufac- 
turer of  garnet  paper  uses  a  specified  size  of  grain  which  he 
calls  No.  1-1/2.  A  competitor  uses  a  slightly  coarser  grain 
which  he,  too,  designates  as  No.  1-1/2,  and  while  the  sizes 
of  the  two  grains  are  so  near  alike  that  detection  with 
the  naked  eye  is  impossible,  it  often  happened  that  the 
manufacturer  using  the  coarser  grain  was  enabled  to  show 
a  slight  efficiency  over  his  competitor,  the  consumer  in  the 
meanwhile  being  ignorant  of  the  fact  that  the  grains  were 
not  the  same.  To  eliminate' misunderstandings  among  the 
consumers,  and  to  bring  competition  to  a  fair  basis,  the 
majority  of  abrasive  paper  and  cloth  manufacturers  of  the 
present  day  use  the  same  sizes  of  grains  for  each  grade. 
Thus  2-1/2,  for  an  illustration,  designates  a  grain  that  has 
passed  through  a  standard  sieve,  the  mesh  of  which  has 
been  agreed  upon. 

In  chinking  of  the  various  grit  numbers  used  to  designate 
the  sizes  of  abrasive  papers  and  cloths,  it  is  sometimes 
advantageous  to  know  how  they  compare  with  the  grain 
numbers  commonly  used  in  sizing  abrasive  materials.  The 
following  table  is  authentic  and  up  to  date,  being  recently 
furnished  by  The  Carborundum  Company. 

Carborundum.         Flint.  Ga  net.  Emery.  Aloxite. 

FF 
F 

220 

i 80        3/0        4/0        3/0        3/0 
150  3/0         2/0         2/0 

I 2O  2/O  O  O 

100  O  2/0  100  100 

90  1/2  O  1/2  1/2 

80  I  I 

7O  1-1/2  1-1/2 

60  I  1/2  2  2 

50  1-1/2  1 

40  2  1-1/2  2-1/2  2-1/2 

36  2-1/2  2 

30  2-1/2          3          3 

24          3          3       3-1/2       3-1/2 

20          3-1/2          3-1/2 

90 


GRITS  AND  GRADES 

By  the  expression  "grade"  we  refer  to  the  relative  hard- 
ness of  a  grinding  wheel.  In  the  early  days  of  the  grinding- 
wheel  industry,  a  few  grades  sufficed.  These  were  known 
generally  as  medium,  medium  hard,  hard,  medium  soft  and 
soft.  As  the  industry  grew,  however,  and  the  grinding 
wheel  became  adapted  to  a  diversity  of  operations,  closer 
and  more  accurate  grades  were  required  which  led  to  the 
adoption  of  somewhat  elaborate  grade  scales.  A  grade  is  a 
certain  value,  within  very  close  limits  at  least.  An  L  grade 
wheel  offers  the  same  resistance  to  disintegration  by  means 
of  the  hand-grading  tool  as  the  grinding -wheel  manu- 
facturer's master  block  in  the  same  grade.  By  way  of 
explanation,  it  may  be  well  to  state  that  all  reliable  grinding- 
wheel  manufacturers  have  a  set  of  master  grade  blocks  as 
standards.  These  are  carefully  made  from  the  correct 
proportions  of  grain  and  bond  to  form  the  various  grades, 
and  are  referred  to  as  a  check  in  determining  the  actual 
grade  of  doubtful  wheels.  Thus  an  M  grade  wheel  made 
by  a  reliable  manufacturer  is  not  somewhere  between  L 
and  M  or  M  and  N  in  which  case  it  might  be  a  de-grade. 
De-graded  wheels  are  used  in  some  cases,  to  be  sure,  but 
they  are  made  as  such.  The  Carborundum  Company  make 
three  de-grades:  G  plus,  H  plus,  and  I  plus. 

The  various  grinding-wheel  manufacturers  use  different 
markings  to  designate  their  various  wheel  grades.  Some 
use  the  letters  of  the  alphabet  (not  always  arranged  the 
same)  while  others  use  numbers,  including  whole  numbers, 
mixed  numbers  and  fractions.  All  grinding-wheel  manu- 
facturers have  comparative  grade  lists,  the  object  of  which 
is  to  show  the  difference  between  their  grades  and  those 
of  their  competitors.  The  writer  has,  from  time  to  time, 
examined  and  compared  many  of  these  grade  lists  and, 
unfortunately,  they  vary  to  such  an  extent  that  it  is  an 
impossibility  to  state  for  a  fact  which  one  is  absolutely 
correct. 

To  compile  a  comparative  grade  list  that  would  satisfy  all 
grinding-wheel  manufacturers,  and,  at  the  same  time,  im- 

91 


ABRASIVES  AND  ABRASIVE  WHEELS 

part  reliable  information  to  the  layman,  the  writer  used  the 
following  method  in  arranging  the  list  here  given.  Taking 
Norton  Company's  grade  list  as  a  basis,  a  chart  was  drawn 
up  on  tracing  paper  including  the  letters  used,  with  spaces 
between  each  for  de-grades.  A  number  of  blue  prints  were 
made  from  this  chart,  one  being  sent  to  every  prominent 
grinding-wheel  manufacturer  in  this  country  with  the  request 
that  they  fill  in  on  the  same,  their  wheel  grades,  showing 
the  comparison  with  Norton  Company's  grading.  Many 
complied  with  the  request,  while  some  declined,  and  the  chart 
in  question  was  compiled  from  the  date  thus  obtained. 
Inasmuch  as  every  individual  grinding-wheel  manufacturer 
knows  more  about  his  own  grades  than  does  his  competitors, 
and  supplied  his  wheel  grades  in  comparison  to  a  given 
standard,  in  this  case  Norton  Company's  grading,  it  is  safe 
to  assume  that  a  comparative  grade  scale  compiled  in  this 
manner  is  as  reliable  as  it  is  possible  to  arrange  the  same. 

The  grinding-wheel  manufacturers  who  use  the  letters 
of  the  alphabet  in  regular  order  as  a  grade  scale  designate 
the  letter  M  as  showing  their  medium  grade.  This  has  led 
many  technical  writers  who  are  not  conversant  with  the 
grinding-wheel  industry  to  show  the  comparison  between 
Carborundum  and  Alundum  wheels  with  the  two  M's 
together.  This  is  a  fallacy,  as  The  Carborundum  Com- 
pany's M  grade  is  equal  to  Norton  Company's  K,  which 
brings  the  L's  of  both  grade  scales  together.  While  both 
The  Carborundum  Company  and  Norton  Company  con- 
sider their  respective  M  grades  as  medium,  they  do  not 
agree  as  to  what  constitutes  a  medium  grade. 

It  is  to  be  regretted  that  the  various  grinding-wheel 
manufacturers  do  not  standardize  on  a  universal  grade 
scale,  which  procedure,  it  is  needless  to  state,  would  elim- 
inate much  confusion.  In  all  probability  they  will  never 
agree  on  a  universal  grade  scale,  the  nature  of  which  would 
cause  them  to  abandon  their  gradings  for  a  standard  already. 

92 


GRITS  AND  GRADES 


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93 


ABRASIVES  AND  ABRASIVE  WHEELS 

in  use,  but  perhaps  if  they  all  agreed  to  adopt  a  universal 
grade  scale,  the  nature  of  which  would  cause  every  manu- 
facturer to  discard  his  present  grade  scale  and  adopt  a  new 
one,  the  change  might  be  brought  about. 

By  referring  to  the  bottom  of  the  comparative  grade 
scale  here  shown,  it  is  seen  that  the  writer  has  had  the  pre- 
sumption to  take  a  step  toward  standardizing  wheel  grades. 
Figures  i  to  22  are  used,  a  space  being  left  between  each 
for  de-grades.  Thus  The  Carborundum  Company's  G-plus 
grade  would  be  designated  13  plus.  A  leading  grinding- 
wheel  manufacturer,  with  whom  the  writer  had  some  cor- 
respondence regarding  wheel  grades,  has  the  following  to 
say  concerning  a  standard  grade  list:  "Nevertheless,  go 
ahead.  We  will  never  get  anywhere  unless  some  one  makes 
the  attempt."  If  a  universal  grade  scale  is  to  be  adopted 
eventually,  the  one  shown  has  merit  in  one  respect  that 
should  not  be  undervalued;  that  is  to  say,  it  would  require 
each  manufacturer  to  discard  his  present  grade  scale,  put- 
ting all  on  the  same  level.  In  this  case,  no  one  manufac- 
turer would  be  in  a  position  to  'state  that  other  manufac- 
turers adopted  his  grade  scale  because  it  was  the  most  com- 
prehensive, or  because  he  was  regarded  as  the  leading  grind- 
ing-wheel  manufacturer. 

It  is  often  stated  on  good  authority,  that  it  is  impossible 
to  arrange  a  grade  scale  which  is  absolutely  reliable  in  all 
respects  and  cases.  In  a  measure,  the  above  statement  is 
correct,  owing  to  the  fact  that  the  abrasive  efficiency  of 
wheels  of  the  same  grade,  but  made  of  different  abrasives, 
or  combinations  of  different  grits,  is  not  always  the  same. 
For  an  illustration,  a  Carborundum  wheel  in  20  grit,  G-plus 
grade,  is  universally  acknowledged  to  be  highly  efficient 
for  grinding  gray  iron  castings.  Now  if  we  should  test  an 
Alundum  wheel  in  Q  .plus,  which  corresponds  in  grade  to 
Carborundum  G  plus,  the  latter  would  prove  low  in  abrasive 
efficiency  because  Alumdum  is  an  alumina  abrasive  not 
adapted  for  grinding  materials  of  low  tensile  strength. 
Again,  suppose  we  had  a  wheel  made  of  pure  corundum  in 

94 


GRITS  AND  GRADES 

46  grit,  M  grade,  vitrified  bond  and  tested  it  in  competition 
with  a  wheel  made  of  the  same  material,  in  the  same  grit 
and  grade,  bonded  by  the  silicate  process.  In  this  case,  we 
would  find  that  the  wheel  made  by  the  vitrified  process  would 
show  the  highest  efficiency,  inasmuch  as  the  silicate  bond 
is  closer;  thus  making  the  wheel  more  compact  and  less 
free  in  cutting.  Further,  if  we  should  test  a  wheel  in  a 
combination  grit  against  one  in  a  straight  grit,  both  being 
of  the  same  material  in  a  like  grade,  one  will  show  high 
efficiency  over  the  other.  However,  let  it  be  assumed  that 
several  manufacturers  agreed  to  make  a  24  x  3  wheel  in 
20  grit,  13  universal  grade  for  the  purpose  of  grinding  drop 
forgings,  and  let  it  be  further  assumed  that  they  used  the 
same  material,  which  could  be  corundum  from  one  mine, 
Aloxite,  Alundum,  Boro-Carbone,  or  in  fact  any  standard 
abrasive.  In  this  case,  it  is  very  probable  that  the  abrasive 
efficiency  of  the  several  wheels  would  be  so  close  that  it 
would  require  the  services  of  an  expert  abrasive  engineer  to 
accurately  determine  which  wheel  really  was  the  most  efficient. 
It  may  seem  out  of  place '  to  many  to  consider  wheel 
speeds  in  connection  with  grades,  but,  as  a  matter  of  fact, 
one  bears  on  the  other  to  a  remarkable  degree,  as  shown 
in  the  data  supplied  by  the  Abrasive  Company  in  another 
chapter.  Let  it  be  assumed  that  we  are  using  a  wheel 
made  of  artificial  corundum  for  grinding  the  flash  marks 
from  drop  forgings,  running  the  same  at  a  peripheral  speed 
of  5,000  feet  per  minute,  and  that  the  wheel  seems  to  wear 
readily.  We  state  at  once  that  the  wheel  is  too  soft.  How- 
ever, if  we  speed  up  the  wheel  slightly,  say  to  a  peripheral 
speed  of  5,300  feet  per  minute,  it  seems  to  appear  harder, 
for  while  it  cuts  just  as  good  as  it  did  previously,  it  does 
not  wear  away  so  readily.  Again,  if  at  a  surface  speed  of 
5, ooo* feet  per  minute  the  wheel  glazed  and  refused  to  cut, 
the  objection  could  be  overcome  by  reducing  the  speed 
slightly.  In  other  words,  it  is  a  good  rule  to  speed  up  a 
wheel  that  appears  soft  and  to  decrease  the  speed  of  one 
that  seems  to  be  unduly  hard. 

95 


ABRASIVES  AND  ABRASIVE  WHEELS 


From  the  foregoing,  it  is  seen  that  speed  has  everything 
to  do  with,  what  the  writer  will  call  for  want  of  a  better 
expression,  the  running  or  working  grade.  As  wheels  wear 
away,  their  speed  should,  of  course,  be  increased  slightly 
to  keep  them  working  at  their  maximum  efficiency.  It  is 
not  always  possible  to  do  this,  however,  and  hundreds  of 
thousands  of  grinding  wheels  are  worn  out  prematurely. 

To  overcome  this  difficulty  by  providing  a  constant  work- 
ing grade,  regardless  of  the  peripheral  speed,  an  American 
inventor  recently  obtained  a  patent  on  a  grinding  wheel 
having  a  gradually  increasing  grade  from  the  periphery  to 
the  hub.  Thus  as  the  wheel  wears,  its  hardness  at  the 
periphery  keeps  increasing,  which  offsets  the  tendency  to 
wear  away  rapidly,  owing  to  the  reduced  surface  speed. 
Wheels  made  by  this  process  should  be  productive  of 
economical  results. 

For  different  grinding  operations,  wheel  speeds  vary 
to  quite  a  remarkable  degree.  The  following  table  shows 
the  speeds  generally  recommended  for  various  grinding 
operations. 


Cylindrical  grinding. 

Surface  grinding 

Automatic  knife  grinding 
Automatic  knife  grinding 

Drill  grinding 

Tool  grinding  (dry) 

Tool  grinding  (wet) 

Cup  wheels  in  general . . . 

General  grinding 

Set-up  polishing  wheels. . 
Vulcanite  wheels 


5,000  to  7,000  feet 
4,000  to  5,000 
2,500  (disc  wheels) 
2 ,000  (cup  wheels) 
4,000  to  4,500 
4,000 
3>500 

3,500 
5,000 
7,500 

10,000 


minute 


CHAPTER  SIX 

TESTING   WHEELS    FOR    EFFICIENCY 

Selection  of  wheels — Improper  methods  of  testing — Practical  testing  methods 
— Items  to  be  noted  in  a  wheel  test — How  to  figure  result — Formula 
for  finding  volume  of  abrasive  material  in  a  wheel — General  considerations 
—Wheel  tests. 

MANUFACTURERS  who  use  grinding  wheels  in  large 
*  T  *  quantities  are  desirous  of  getting  the  most  efficient 
wheel  for  a  specific  purpose.  To  determine  which  is  the 
most  efficient  abrasive  or  make  of  wheel,  and,  further, 
what  grit  and  grade  of  any  particular  make  of  wheel  is  the 
most  desirable  to  use  for  a  predetermined  purpose,  is  not 
an  offhand  procedure.  Results  that  can  be  relied  upon 
are  arrived  at  only  by  carefully  conducted  tests  arranged 
along  practical  lines.  Grinding-wheel  manufacturers  are 
frank  to  admit  that  there  is  no  absolute  rule  for  the  selection 
of  grits  and  grades  as  the  following,  which  appears  on  page 
96,  1916  edition  of  Norton  Company's  catalogue,  plainly 
states:  "Conditions  under  which  grinding  wheels  are  used 
vary  to  such  an  extent  that  no  absolute  rule  can  be  given 
for  selecting  the  right  grades  for  the  work." 

Because  a  certain  kind  of  wheel  gives  entire  satisfaction 
in  one  plant,  is  no  indication  that  it  will  do  equally  well  in 
another  shop,  even  though  the  work  is  identical  in  both 
cases.  The  reason  for  this  is  that  local  conditions  generally 
have  to  be  taken  into  consideration  and  as  they  often  can- 
not be  altered,  it  is  best,  when  practicable,  to  test  trial 
wheels  on  actual  routine  work  under  the  supervision  of 
careful  and  painstaking  efficiency  engineers  who  have  some 
knowledge  of  abrasives  and  grinding  practice. 

To  give  a  trial  wheel  to  the  grinder  with  the  injunction : 
07 


ABRASIVES  AND  ABRASIVE  WHEELS 

"Here,  Bill,  try  this  wheel  and  see  what  you  think  of  it," 
is  one  way  of  testing  a  trial  wheel  and  a  practice  that  is 
too  prevalent  with  many  grinding-wheel  consumers.  Bill 
may  have  the  best  intentions  in  the  world,  but  it  requires 
more  than  good  intentions  to  test  a  grinding  wheel  to 
determine  its  actual  worth.  He  uses  the  wheel  for  a  day 
or  so,  maybe  a  week,  and  then  forms  a  decision  which  may 
or  may  not  be  correct.  He  is  not  to  blame  in  nine  cases 
out  of  ten  if  his  verdict  is  incorrect  because  the  actual  user 
of  grinding  wheels,  on  rough  operations  at  least,  has  but 
little  use  for  mathematics,  therefore  he  is  at  a  loss  to  form 
an  accurate  decision  regarding  actual  cost  of  production. 
In  his  opinion,  the  wheel  may  be  a  good  one  or  a  poor  one. 
Unless  the  wheel  shows  a  remarkable  saving  in  grinding 
time,  his  decision  is  liable  to  be  a  guess  pure  and  simple 
and  it  may  be  influenced  by  a  deep-rooted  prejudice  in 
favor  of  a  certain  make  of  wheel.  He  may  use  a  trial  wheel 
for  a  few  weeks  and  report  that  he  sees  no  apparent  saving, 
and  if  the  wheel  in  question  happens  to  be  a  comparatively 
high-priced  one,  the  test  is  ended  then  and  there. 

On  the  other  hand,  if  the  wheel  was  tested  according  to 
common-sense  methods  the  production  department  would 
have  actual  figures  to  show  the  purchasing  department 
regarding  the  actual  earning  power  of  the  wheel.  There 
are  over  twenty  grinding-wheel  manufacturers  in  this 
country  and  they  all  make  reliable  products.  They  have 
brought  the  grinding-wheel  industry  to  its  present  high 
state  of  development  through  tireless  and  painstaking  effort, 
being  ready  at  any  time  to  make  special  wheels  for  trial 
purposes  for  any  operation  that  appears  practicable.  Since 
they  are  ever  ready  to  help  the  manufacturer  in  reducing 
his  production  costs,  why  should  not  the  manufacturer 
meet  them  half-way  by  giving  trial  wheels  a  fair  and  im- 
partial test? 

The  average  manufacturer  is  broad-minded;  he  is  gen- 
erally willing  to  grant  the  grinding-wheel  salesman  a 
courteous  interview  and  often  orders  trial  wheels  for  test 

98 


TESTING  WHEELS  FOR   EFFICIENCY 

purposes.  After  the  wheels  have  been  tested,  however,  it 
is  seldom  that  the  salesman  who  supplied  them  is  able  to 
get  an  accurate  report  of  their  performance.  Unless  the 
saving  is  readily  apparent,  as  in  testing  Carborundum  against 
emery  for  cast-iron  grinding  for  instance,  the  trial  wheel 
is  in  many  cases  reported  as  showing  no  saving  as  com- 
pared with  the  wheels  regularly  used. 

A  report  of  this  kind,  lacking  in  figures  to  verify  it,  is 
unsatisfactory  to  all  parties  concerned.  The  consumer  does 
not  know  for  a  certainty  whether  the  wheel  tested  actually 
did  or  did  not  show  efficiency;  the  salesman  is  at  a  loss 
to  make  an  intelligent  report  to  his  employer;  while  the 
grinding-wheel  manufacturer,  although  compelled  to  ac- 
knowledge defeat  in  the  specific  case  in  question,  js  justified 
in  forming  the  conclusion  that  his  wheel  was  not  given  a 
fair  test  since  no  figures  were  submitted  to  verify  the 
unsatisfactory  report. 

In  analyzing  the  above  case,  we  must  admit  that  the 
salesman  exercised  the  talents  of  his  profession  in  getting 
permission  to  submit  a  sample  of  his  product  for  test  pur- 
poses, while  the  grinding-wheel  manufacturer  did  his  part 
in  supplying  a  test  wheel  made  to  meet  the  grinding  con- 
ditions as  specified  on  the  salesman's  trial  order.  The 
consumer,  however,  to  state  the  case  in  plain  English, 
condemned  the  wheel  without  furnishing  any  figures  to 
substantiate  his  claim. 

A  few  cases  have  been  called  to  the  writer's  attention 
wherein  a  trial  order  was  given  solely  for  the  purpose  of 
getting  rid  of  a  persistent  salesman  and  an  unsatisfactory 
report  submitted  to  discourage  further  effort  on  the  sales- 
man's part.  A  procedure  of  this  kind  is  unjust  and  not  in 
accordance  with  good  business  ethics.  To  give  the  majority 
of  successful  manufacturers  credit,  however,  we  are  safe 
in  stating  that  cases  like  the  above  are  happily  not  common. 

We  certainly  are  not  justified  in  condemning  all  manu- 
facturers at  large  for  their  apparent  lack  of  interest  in 
grinding-wheel  tests,  and  the  only  reason  the  writer  can 

99 


ABRASIVES  AND  ABRASIVE  WHEELS 


assign  for  this  state  of  affairs  is  that  the  average  manufac- 
turer is  not  an  abrasive  engineer,  therefore  he  lacks  tech- 
nical knowledge  of  grinding  wheels  and  often  does  not  use 
the  practical  methods  employed  by  the  abrasive  efficiency 
engineer  in  determining  the  actual  earning  power  of  a 
grinding  wheel.  In  conducting  a  grinding-wheel  test  em- 
bracing wheels  of  several  makes,  or  a  few  wheels  of  the  same 
make  in  different  grits  and  grades,  it  is  a  waste  of  time  to 
attempt  to  state  from  observation  alone  which  is  the  most 
efficient  wheel.  A  careful  record  of  each  wheel  should  be 
kept  and  reliable  figures  submitted  to  use  in  comparing 
the  different  wheels. 

To  illustrate  the  principle  of  practical  wheel  testing  as 
graphically  as  possible,  it  may  be  well  to  consider  a  few 
practical  tests.  Where  a  large  number  of  comparatively 


Fig.  20. — Ideal  shape  of  castings  for  testing  economy  of  wheels. 

small  pieces  are  ground,  we  have  ample  opportunity  to 
determine  the  actual  earning  power  of  the  grinding  wheel 
by  considering  the  following  factors:  Time  consumed, 
number  of  pieces  ground,  value  of  abrasive  material  used 
and  the  cost  of  labor.  By  comparing  the  amount  of  work 
produced  with  the  actual  cost  involved,  we  readily  determine 
the  actual  grinding  cost  per  thousand  pieces.  This  is  what 

100 


TESTING  WHEELS  FOR   EFFICIENCY 

interests  the  successful  manufacturer — actual  production 
costs.  What  the  grinding  wheel  is  made  of  does  not  matter 
as  far  as  he  is  concerned;  if  wheels  made  of  river  sand 
bonded  with  molasses  showed  the  greatest  earning  power 
he  would  accept  them  just  as  readily  as  he  does  the  com- 
paratively high-priced  products  of  the  electric  furnace. 

In  Fig.  20  is  shown  an  ideal  casting  for  making  an  effi- 
ciency test.  It  is  of  malleable  iron  weighing  10-1/2  oz., 
and  the  only  grinding  necessary  is  at  the  base  to  remove 
the  sprue  left  when  the  casting  was  knocked  off  the  gate. 
Let  it  be  assumed  that  we  are  to  test  a  1 6  x  2  wheel  for 
grinding  these  pieces.  The'  workman  is  given  the  wheel 
together  with  an  unlimited  supply  of  castings  and  the  test 
conducted  for  a  period  of  fifty  hours.  At  the  end  of  this 
time,  we  might  have  a  report  like  the  following:  Number 
of  pieces  ground  2,000,  time  consumed  50  hours,  weight 
of  wheel  after  test  30  Ibs.  In  the  meantime,  we  have 
drawn  up  a  form  like  the  following  to  aid  us  in  determining 
the  grinding  cost. 

Part  tested Rocker  arm  short  bracket 

Make  of  wheel Duplex 

Size 16  x  2 

Grit 20 

Grade Q 

Bond Vitrified 

Cost $6.63 

Weight 34  Ibs. 

Cost  per  pound $00.195 

Operating  speed 1,200  R.P.M. 

Material  ground Malleable  iron 

Length  of  test 50  hours 

Workman's  name G.  Harris 

Workman's  rate $0.25  per  hour 

Number  of  pieces  ground 2,000 

Cost  of  labor $i 2.50 

Weight  of  wheel  after  test 30  Ibs. 

Pounds  of  abrasive  used 4 

Value  of  abrasive  used $0.78 

Tota  cost  of  gr'nding $13.28 

Cost  per  thousand  pieces $6.64 

Cost  per  piece $0.00664 

101 


ABRASIVES  .AND  ABRASIVE  WHEELS 

Here  we  have  sufficient  data  to  satisfy  the  most  critical 
efficiency  engineer.  Nothing  is  contained  in  the  above  that 
is  superfluous;  in  fact  every  item  is  for  a  distinct  purpose. 
The  total  grinding  cost  means  something  because  it  repre- 
sents actual  dollars  and  cents  that  have  been  expended  on 
a  certain  operation.  How  much  better  it  is  to  have  a 
statement  like  the  above  than  to  rely  upon  the  foreman's 
statement  that  a  certain  wheel  cuts  good  and  that  one  of 
them  lasts  the  operator  three  months.  This  statement 
conveys  no  real  information  as  regards  actual  production 
costs.  Suppose,  for  the  sake  of  an  argument,  that  he  tried 
another  make  of  wheel  which  lasted  only  two  months. 
He  would,  in  all  probability,  condemn  it  as  too  short- 
lived, never  taking  into  consideration  that  a  practical  test 
as  outlined  above  might  prove  that  it  actually  reduced 
grinding  costs  while  it  lasted.  The  first  cost  of  a  grinding 
wheel  is  of  no  consideration;  it  is  its  earning  power  that 
should  be  known  to  be  appreciated.  To  illustrate  the 
point  clearly,  let  us  consider  a  cheap  wheel. 

As  in  the  previous  test,  we  will  use  a  16  x  2  wheel,  but 
of  such  a  quality  that  it  can  be  purchased  at  a  rock-bottom 
price  of  $4.54.  Owing  to  the  low  price  of  the  wheel,  it 
naturally  follows  that  it  cannot  be  made  of  a  very  expensive 
abrasive,  the  ultimate  result  being  that  it  is  slow  cutting 
when  compared  with  wheels  that  bring  better  prices.  As 
before,  the  workman  is  given  an  unlimited  number  of  cast- 
ings, the  wheel  weighed,  and  the  test  run  for  fifty  hours. 
At  the  expiration  of  the  test,  we  might  have  the  following 
report:  Number  of  pieces  ground  1,500.  Time  consumed 
50  hours.  Weight  of  wheel  after  test  28  pounds.  From 
this  report  we  proceed  as  before  and  draw  up  a  summary. 

Part  tested Rocker  arm  short  bracket 

Make  of  wheel Complex 

Size 16  x  2 

Grit 20 

Grade Q 

Bond Vitrified 

Cost $4.54 

102 


TESTING  WHEELS  FOR   EFFICIENCY 

Weight 34  Ibs. 

Cost  per  pound $0.13325 

Operating  speed 1,200  R.P.M. 

Material  ground Malleable  iron 

Length  of  test 50  hours 

Workman's  name G.  Harris 

Workman's  rate $0.25  per  hour 

Number  of  pieces  ground i;5°o 

Cost  of  labor $12.50 

Weight  of  wheel  after  test 28  Ibs. 

Pounds  of  abrasive  used 6 

Value  of  abrasive  used $0.7995 

Total  cost  of  grinding $13.2995 

Cost  per  thousand  pieces $8.866 

From  this  test,  it  is  seen  that  it  cost  more  to  use  the  cheap 
wheel  than  it  did  to  use  the  moderate-priced  one.  As  a 
general  thing  the  purchasing  agent  sees  the  first  cost  only, 
and  as  long  as  he  can  keep  his  purchases  at  a  low  figure  he 
is  not  concerned  with  actual  operating  expenses  in  the 
production  department.  In  due  justice  to  the  purchasing 
agent,  however,  he  should  not  be  blamed  for  buying  at 
as  low  a  cost  as  possible  when  the  shop  management  is  not 
armed  with  figures  to  show  actual  grinding  costs  for  dif- 
ferent operations.  It  is  the  purchasing  agent's  duty  to 
buy  standard  goods  at  the  best  prices  obtainable  and  it  is 
up  to  the  shop  to  test  the  material  purchased  to  see  that 
it  is  efficient. 

In  carrying  the  test  farther,  let  it  be  assumed  that  we  have 
bought  a  high-priced  wheel  for  test  purposes,  the  same 
costing  us  $9.27  or  over  twice  the  price  paid  for  the  wheel 
previously  tested.  It  is  tested  in  the  same  manner  as  the 
previous  wheels  and  the  following  report  submitted:  Num- 
ber of  pieces  ground  3,000,  time  consumed  50  hours,  weight 
of  wheel  after  test  25  Ibs.  As  before  we  draw  up  a  summary 
from  the  report. 

Part  tested Rocker  arm  short  bracket 

Make  of  wheel Simplex 

Size 16  x  2 

Grit 20 

103 


ABRASIVES  AND  ABRASIVE  WHEELS 

Grade : .  H  pi. 

Bond Vitrified 

Cost $9.27 

Weight 34  Ibs. 

Cost  per  pound $0.2726 

Operating  speed 1,200  R.P.M. 

Materia'  ground . Malleable  iron 

Length  of  test 50  hours 

Workman's  name G.  Harris 

Workman's  rate $0.25  per  hour 

Number  of  pieces  ground 3,000 

Cost  of  labor $12.50 

Weight  of  wheel  after  test 25  Ibs. 

Pounds  of  abrasive  used 9 

Value  of  abrasive  used $2.4534 

Total  cost  of  grinding $14.9534 

Cost  per  thousand  pieces $4.9844 

It  is  seen  that  by  using  a  first-class  abrasive  we  have 
actually  reduced  our  grinding  cost,  although  the  first  cost 
of  the  wheel  was  over  twice  that  of  the  wheel  previously 
tested  and  the  wear  per  week  is  50  per  cent,  greater. 

If  a  wheel  seems  to  wear  rapidly  there  is  no  cause  for 
alarm,  for  it  must  be  borne  in  mind  that  the  ideal  grade  of 
grinding  wheel  for  a  specific  operation  is  of  just  the  correct 
degree  of  hardness  to  allow  the  particles  of  abrasive  material 
to  be  pulled  from  the  bonding  material  as  soon  as  they  have 
lost  their  cutting  power.  A  hard  wheel  will  last  longer 
than  a  soft  one,  to  be  sure,  but  at  the  same  time  its  earning 
power  is  greatly  reduced,  as  it  is  slow  cutting.  It  is  a  very 
good  plan  to  determine  the  earning  power  of  a  wheel  before 
condemning  it  for  .wearing  out  too  rapidly.  There  is,  of 
course,  a  limit  beyond  which  we  cannot  go  in  installing 
comparatively  soft  wheels  for  rough  work.  If  the  wheel 
is  too  soft,  the  grains  of  the  abrasive  will  be  pulled  from  the 
bonding  material  before  accomplishing  a  fair  amount  of 
work.  Instead  of  removing  metal  from  the  work,  we  are 
truing  off  the  grinding  wheel. 

That  a  softer  grade  will  oftentimes  accomplish  more  work 
on  a  given  operation'  is  a  fact  known  to  every  grinding- 
wheel  salesman,  and  the  following  incident  which  carre  to 

104 


TESTING  WHEELS  FOR   EFFICIENCY 

the  writer's  notice,  may  be  of  interest  while  considering  this 
factor.  The  work  in  question  consisted  of  cast-iron  cream- 
separator  frames  which  were  ground  all  over  with  the  object 
of  preparing  an  even  surface  for  the  painter.  Here  it  was 
necessary  to  go  over  the  surface  of  the  casting  carefully, 
and  as  this  was  somewhat  of  a  tedious  operation  at  best, 
a  free  cutting  wheel,  which  would  enable  the  operator  to 
finish  a  frame  in  the  quickest  possible  time,  was  very  much 
desired. 

With  the  work  in  question,  the  operator  had  been  using 
Carborundum  wheels  8  in.  dia.,  i  in.  face,  30  grit,  G  pi. 
grade  in  V  A  bond.  The  output  with  this  wheel  was 
thirty  castings  per  day.  One  day,  one  of  The  Carborundum 
Company's  efficiency  engineers  investigated  the  operation 
and  induced  the  management  to  try  wheels  of  a  softer  grade, 
stating  that,  while  the  softer  wheel  would  not  last  as  long, 
it  would  materially  increase  production  while  it  lasted. 
The  result  was  that  wheels  in  30  grit  H  pi.  grade  were  tried 
out  and,  much  to  the  operator's  surprise,  he  was  enabled 
to  finish  fifty  castings  per  day. 

Assuming  that  we  were  conducting  a  test  of  this  kind  today 
we  would  use  a  day's  wage  of  $3.00  as  a  basis  on  which  to 
conduct  our  cost  test.  In  finishing  thirty  castings  per  day, 
our  grinding  cost  for  labor  would  be  ten  cents  per  casting 
as  against  six  cents  per  casting  when  fifty  are  ground  per 
day.  Thus,  it  is  seen  that  an  actual  saving  of  40  per  cent, 
in  production  cost  is  accomplished  through  a  little  experi- 
ment in  changing  the  grade  of  the  wheel. 

A  slight  change  in  grade  often  makes  a  great  difference, 
as  the  above-mentioned  test  illustrates,  and  another  simple 
experiment  along  the  same  lines,  that  came  to  the  writer's 
attention  a  few  years  ago,  may  be  of  interest.  In  any 
farming  country  may  be  found  blacksmiths  and  others  who 
net  quite  a  sum  annually  grinding  plow  points  during  the 
plowing  season.  The  operation  is  simple,  consisting  of 
grinding  the  plow  point  until  it  is  sharp.  To  the  city-bred 
man  it  may  seem  laughable  that  the  point  of  a  plow  has  to 


ABRASIVES  AND  ABRASIVE  WHEELS 

be  sharp,  but  such,  nevertheless,  is  well  known  by  those 
who  have  had  occasion  to  guide  a  plow. 

The  man  in  question  used  a  Carborundum  wheel  in  20 
grit,  G  pi.  grade  and  V  A  bond  with  which  he  could  grind 
forty  plow  points  per  day,  netting  him  $8.00.  He  was 
dubious  about  trying  a  softer  wheel,  claiming  that  $8.00 
per  day  was  a  nice  little  sum  in  itself  and  that  it  was  some- 
times a  good  plan  to  let  well  enough  alone.  However,  he 
was  induced  to  try  a  wheel  one  grade  softer,  that  is  H  pi., 
with  the  result  of  grinding  sixty  points  per  day,  netting  him 
$12.00.  It  is  seen  that  by  using  a  wheel  more  adapted  for 
his  work  he  put  $4.00  extra  in  his  pocket  daily  during  the 
plow-point  grinding  season. 

Now  the  business  of  grinding  plow  points  in  a  country 
cross-roads  shop  may  not  amount  to  much  in  itself,  but 
that  is  not  the  point.  The  lesson  is  here:  If  one  man, 
who  knows  but  little  of  efficiency  from  the  average  manu- 
facturer's point  of  view,  can  put  an  extra  $4.00  in  his  pocket 
every  day,  using  one  wheel  only,  the  same  being  graded 
properly,  what  are  the  possibilities  for  saving  with  the 
manufacturer  whose  grinding- wheel  bill,  and  subsequent 
grinding  costs,  runs  into  big  figures?  The  possibilities  for 
saving  are  enormous. 

The  tests  so  far  considered  have  dealt  only  with  com- 
paratively light  work,  but  from  this  it^rnust  not  be  inferred 
that  accurate  tests  for  production  costs  cannot  be  conducted 
on  heavy  work.  Car-wheel  grinding  furnishes  an  ideal 
means  of  determining  the  efficiency  of  a  grinding  wheel 
on  heavy  work,  and  the  following  test,  which  came  to  the 
writer's  notice  a  few  years  ago,  embodies  all  the  data 
necessary  for  computing  the  actual  grinding  cost  per  wheel. 

The  work  consisted  of  grinding  the  small  fins  left  by  the 
molds  on  Barr  contracted  chilled-iron  car  wheels,  often  used 
on  freight  cars.  The  work  was  done  on  a  car- wheel  grinder, 
of  regular  pattern,  and  the  wheel  used  was  Carborundum 
18  in.  dia.,  4-1/4  in.  face,  166  grit,  G  pi.  grade  and  V  A 
bond.  The  average  grinding  time  was  50  seconds  per 

1 06 


TESTING  WHEELS  FOR   EFFICIENCY 

wheel  and  in  72  working  days  of  ten  hours  each,  the  wheel 
was  reduced  to  a  diameter  of  11-3/4  inches.  If  the  wheel 
had  been  used  constantly,  ten  hours  per  day,  it  would  have 
ground  8,640  car  wheels.  This  is,  of  course,  a  theoretical 
calculation  as  a  certain  amount  of  time  was  consumed  in 
taking  the  car  wheels  to  and  from  the  grinder  and  in  mount- 
ing them  for  the  grinding  operation.  As  it  was,  6,343  car 
wheels  were  actually  ground  during  the  test  of  72  days. 

Let  us  assume  that  the  operator  of  the  car- wheel  grinder 
receives  $2.50  per  day,  and  proceed  to  ascertain  our  grind- 
ing cost  per  wheel.  As  72  x  2.50  =  180,  we  have  a  cost  of 
$180.00  for  labor.  A  Carborundum  wheel  18  x  4-1/4 
inches  costs  $13.07,  but  in  the  case  in  question  it  was  not 
completely  worn  out,  therefore  we  will  compute  the  actual 
cost  of  the  abrasive  used.  Instead  of  considering  the 
number  of  pounds  of  abrasive  used  we  will,  for  the  sake  of 
variety,  use  another  method  of  figuring  the  cost  of  a  partial 
wheel  by  ascertaining  its  volume  in  cubic  inches  and  sub- 
tracting the  number  of  cubic  inches  in  the  worn  portion 
of  the  wheel,  which  will  give  us  the  number  of  cubic  inches 
actually  used  in  grinding  the  6,343  car  wheels.  Knowing  the 
volume  of  the  new  wheel  and  its  value  it  is  an  easy  matter 
to  find  the  value  per  cubic  inch  and  also  the  value  of  the 
amount  of  abrasive  used. 

To  find  the  volume  of  an  18  x  4-1/4  grinding  wheel, 
we  can  use  the  following  formula,  in  which  V  stands  for 
volume,  D  for  diameter,  W  for  width,  while  the  decimal 
.7854  is  a  constant. 

V  =  .7854xDxW 

Thus,  .7854  x  1 8  x  18  x  4-1/4  =  1,044.3168  cubic  inches, 
which  is  the  volume  of  an  18  x  4-1/4  wheel. 

Again,  .7854  x  11-3/4  x  11-3/4  x  4-1/4  =  445.0026  cubic 
inches,  which  is  the  volume  of  a  11-3/4  x  4-1/4  wheel. 

Further,  if  1,044.3168  cubic  inches  of  material  cost  $13.07, 
ore  cubic  inch  will  cost  $0.01251. 

By  subtracting  445.0026  cubic  inches  from  1,044.3168 
cubic  inches,  we  have  599.2905  cubic  .inches  as  the  amount 

107 


ABRASIVES  AND  ABRASIVE  WHEELS 

of  material  used.  Multiplying  this  amount  by  the  cost 
per  cubic  inch,  we  have  $7.4971  or  the  actual  cost  of 
abrasive  used.  Adding  this  to  $180.00,  our  labor  cost,  we 
have  a  total  cost  of  $187.4871. 

We  will  call  our  cost  $187.50  for  convenience  in  figuring, 
and  dividing  this  amount  by  6,343,  the  number  of  car 
wheels  ground,  we  find  an  actual  grinding  cost  of  $0.02956 
per  wheel  or  $29.56  per  thousand  wheels.  It  is  seen  that 
by  using  a  simple  practical  method  it  is  possible  to  accurately 
determine  the  grinding  cost  under  everyday  working  con- 
ditions. It  is  reliable  figures  of  this  kind  that  the  manufac- 
turers desire. 

In  grinding  comparatively  large  work,  it  is  possible  to 
determine  the  grinding  cost  while  working  on  an  individual 
piece,  as  the  following  report  on  the  grinding  of  a  large 
chilled-iron  roll,  by  Mr.  J.  H.  Hollinger,  of  The  Landis 
Tool  Company,  published  in  the  Oct.  26,  1911,  number  of 
the  American  Machinist,  graphically  illustrates. 

"I  have  ground  a  chilled  cast-iron  roll  20-3/16  inches 
diameter  by  28  inches  long  on  a  Landis  20x96  inch  roll 
grinder,  removing  1/4  inch  from  the  diameter  of  the  body 
only.  Surface  speed  of  roll,  roughing  52-1/2  feet,  finishing 
52—1/2  feet;  traverse  of  wheel  for  each  revolution  of  the 
work,  7/8  inch;  wheel  feed  at  each  reversal,  0.006  inch 
for  roughing;  o.ooi  inch  for  finishing.  The  roll  was  ground 
with  a  22-9/16x2  inch  Carborundum  wheel  having  an  8- 
inch  hole,  403  grit,  P  grade,  O  F  bond,  running  at  925 
revolutions  per  minute,  5,472  surface  feet  and  it  was  re- 
duced in  diameter  19/32  inch,  which  represents  a  cost  of 
90  cents.  This  wheel  wore  just  fast  enough  to  keep  itself 
sharp  and,  for  roughing,  was  only  dressed  once  with  a 
diamond.  Time  for  grinding  the  roll  to  a  smooth  finish, 
good  enough  for  hot  rolling,  4  hours;  total  cubic  inches 
removed,  221 ;  cubic  inches  removed  per  minute  to  finished 
surface,  0.92  inch.  The  motor  used  on  this  work  was  a 
variable  speed  25  horsepower.  Average  horsepower  con- 
sumed, 21." 

108 


TESTING  WHEELS   FOR   EFFICIENCY 

In  the  above  report  it  is  seen  that  Mr.  Hollinger  has 
embodied  all  the  data  necessary  for  computing  an  accurate 
grinding  cost,  which  is  quite  essential  when  testing  wheels 
on  large  work.  It  is  needless  to  state  that  comparatively 
long  grinding  operations  on  large  pieces  are  expensive  and 
without  accurate  data,  compiled  by  one  who  understands 
the  art  of  grinding  thoroughly,  it  is  an  impossibility  to  de- 
termine the  actual  cost. 

The  operation  shown  in  Fig.  21,  furnishes  another  in- 
stance wherein  the  grinding  cost  can  be  computed  through 


Fig.  21. — Grinding  long  shafting  used  in  textile  machinery. 

working  on  one  piece.  The  work  in  question  consists  of 
actually  grinding  long  shafting  used  in  textile  machinery. 
The  shafting  comes  slightly  oversize  and  after  being  centered 
is  kept  in  racks  and  ground  as  needed.  With  shafts  of  the 
same  length  and  with  a  like  amount  of  material  to  remove, 
it  is  obvious  that  a  record  of  the  grinding  cost  for  each  size 
can  be  kept.  When  another  make  of  wheel  is  to  be  tested, 
it  is  a  simple  matter  to  determine  its  earning  power  by 

109 


ABRASIVES  AND  ABRASIVE  WHEELS 

noting  the  length  of  time  taken  to  remove  a  certain  amount 
of  material  and  the  wheel  wear  meanwhile. 

Still  another  instance  where  the  grinding  cost  can  be 
computed  while  working  on  one  comparatively  large  piece 
is  shown  in  Fig.  22.  In  this  case,  the  work  consists  of 
grinding  locomotive  guide  bars  to  produce  a  smooth  and 


Fig.  22. — Grinding  a  locomotive  guide  bar. 

true  surf  ace  for  the  cross-head  gibs  to  slide  upon.  Different 
types  of  locomotives  have  various  kinds  of  guide  bars, 
but  with  the  kind  shown  four  constitute  a  set.  Thus,  to 
determine  the  grinding  cost,  all  that  is  necessary  is  to 
measure  the  thickness  of  the  wheel  with  a  pair  of  calipers 
before  and  after  grinding  the  four  bars  and  taking  note  of 
the  time  consumed  in  the  grinding  operation.  The  actual 
grinding  cost  is  arrived  at  by  adding  the  labor  cost  and 
value  of  abrasive  material  used.  In  tests  of  this  kind,  it  is 
truly  surprising  how  some  makes  of  wheels  show  remarkable 

no 


TESTING  WHEELS  FOR   EFFICIENCY 


saving  in  grinding  costs  over  others.  Thus  the  man  who 
thinks  that  it  is  not  worth  while  to  test  grinding  wheels  for 
efficiency  is  often  needlessly  grinding  away  dollars,  so  to 
speak,  instead  of  removing  metal  in  the  most  efficient  man- 
ner possible.  It  must  be  borne  in  mind  that  grinding 
operations  on  large  work  are  expensive  at  best  and  too 
much  cannot  be  said  in  favor  of  making  accurate  tests 
to  determine  actual  grinding  costs. 

On  certain  classes  of  grinding  of  an  automatic  or  semi- 
automatic nature,  wherein  the  actual  time  of  contact  be- 


Fig.  23. — Type  of  chain  links  finished  by  semi-automatic  grinding. 

tween  the  wheel  and  the  work  does  not  vary,  the  efficiency 
of  the  wheel  can  be  determined  by  considering  one  factor 
only,  that  is  the  actual  number  of  hours  it  lasts.  The 
operation  of  grinding  chain  links  of  the  kind  illustrated  in 
Fig.  23  furnishes  an  excellent  means  of  determining  the  earn- 
ing power  of  a  grinding  wheel  by  considering  its  life  only. 
Chain  links  of  this  kind  are  used  for  transmitting  power, 

.in 


ABRASIVES  AND  ABRASIVE  WHEELS 

conveying  material,  etc.,  and  are  made  in  various  sizes  from 
small  ones  approximately  an  inch  long  to  large  sizes  a  foot  or 
more  in  length.  The  smaller  sizes  are  cast  from  a  gated 
pattern  and  the  object  of  the  grinding  is  to  remove  the  gate. 
This  gate  is  shown  on  the  top  of  the  link  illustrated  in  Fig.  23. 
The  means  generally  provided  for  this  work  are  shown 
in  Fig.  24,  wherein  A  is  the  grinding  wheel  revolving  as 
shown  by  the  arrow  and  B  the  drum  for  carrying  the  links 


Fig.  24. — Principle  involved  in  grinding  chain  links. 

which  are  placed  by  hand  in  depressions,  or  pockets,  pro- 
vided to  accommodate  them.  This  drum  revolves  quite 
slowly  in  the  direction  shown  by  the  arrow.  The  object 
of  the  slow  motion  is  to  give  the  wheel  ample  time  to  grind 
away  the  gate.  The  operator  places  the  links  in  the  pockets 
by  hand  and  as  the  drum  revolves  they  are  brought  in 
contact  with  the  wheel.  Means  are  provided  for  moving 
the  shaft  carrying  the  drum  toward  the  wheel  as  it  wears 
away,  which  is,  of  course,  necessary  in  producing  uniform 
work.  As  the  speed  of  the  drum  is  always  constant,  it  is 


TESTING  WHEELS   FOR   EFFICIENCY 

evident  that  the  life  of  the  wheel  is  the  chief  factor  to  con- 
sider, as  a  comparatively  soft  wheel  would  wear  away  very 
rapidly  without  performing  its  full  quota  of  work  and  during 
its  life  would  require  almost  constant  attention  in  keeping 
the  drum  in  proper  relation  to  the  periphery  of  the  wheel: 


Fig.  25. — Semi-automatic  machine  for  rounding  the  backs  of  pearl  buttons. 

On  the  other  hand,  the  wheel  should  not  be  too  hard  or 
it  would  glaze  very  readily,  refuse  to  cut,  and  in  some  cases 
a  fractured  wheel  would  result.  In  testing  wheels  on  work 
of  this  kind,  it  is  a  good  plan  to  begin  the  test  with  com- 
paratively soft  wheels,  taking  note  of  the  amount  of  links 
of  a  given  size  ground  during  the  life  of  the  wheel.  Harder 
wheels  are  then  tried  and  the  hardest  wheel  that  will  cut 
satisfactorily  without  constant  glazing  is  the  one  that  should 
be  selected. 


ABRASIVES  AND  ABRASIVE  WHEELS 

Another  case  wherein  the  efficiency  of  the  wheel  is  de- 
termined by  its  life  is  illustrated  in  Fig.  25.  The  machine 
shown  is  of  semi-automatic  construction  and  is  designed 
for  rounding  the  backs  of  pearl-button  blanks.  As  the  illus- 
tration shows,  the  operator  has  a  box  of  button  blanks 
and  places  them  one  at  a  time  in  the  chucks  which  au- 
tomatically grip  them  and  carry  them  under  the  wheel 
shown  at  the  right.  The  face  of  the  wheel  is  slightly  con- 
caved and  as  the  chucks  revolve  on  their  axes,  as  well  as 
traveling  in  a  circle,  the  blanks  are  given  the  desired 
rounded  shape  as  they  pass  under  the  wheel.  Provided 
the  blanks  are  ground  in  a  satisfactory  manner,  that  is, 
without  burning  them,  the  wheel  that  will  last  the  greatest 
number  of  working  days  is  considered  the  most  efficient. 
Tests  of  the  above  kind  are,  of  course,  easily  conducted  as 
they  consist  simply  of  selecting  a  wheel  that  will  do  the 
work  in  a  satisfactory  manner  and  noting  how  long  it  will 
last. 

From  the  foregoing,  it  is  seen  that  there  are  three  practical 
methods  used  for  testing  the  efficiency  of  a  grinding  wheel. 

1.  A  definite  time  test  wherein  the  wheel  is  used  for  a 
specified  number  of  hours ;  the  grinding  cost  being  computed 
by  adding  the  value  of  the  abrasive  used  to  the  labor  cost ; 
from  which  the  grinding  cost  per  piece  or  per  hundred  or 
thousand  pieces  is  computed. 

2.  The  individual  piece  test,  wherein  the  grinding  time 
and  cost  of  abrasive  is  noted  while  working  on  one  piece 
of  comparatively  large  work. 

3.  The  life  of  wheel  test  in  which  the  amount  of  grinding 
is  noted  during  the  whole  time  the  wheel  is  in  service. 

All  the  above  tests  are  practical,  and  can  be  relied  upon 
to  give  accurate  production  costs  on  a  variety  of  work; 
both  of  a  rough  and  precision  nature. 

Grinding-wheel  tests  should,  of  course,  be  conducted  by 
responsible  men  and  the  data  regarding  the  performance  of 
each  wheel  should  be  kept  accurately,  otherwise  the  tests 
will  be  of  no  practical  value. 

114 


CHAPTER  SEVEN 

LABORATORY   TESTS 

Apparatus  and  appliances  used — Limitations  of  laboratory  tests — Factors 
to  be  considered — Laboratory  testing  machine — Data  for  test — Work 
used  in  testing. 

THE  simple  methods  used  in  testing  grinding  wheels  on 
actual  work,  as  described  in  the  previous  chapter, 
can  be  used  only  in  cases  where  there  are  comparatively 
long  runs  of  routine  work.  In  many  instances,  however, 
the  work  is  of  such  a  nature  that  it  is  an  impossibility  to 
secure  enough  like  pieces  on  which  to  test  the  efficiency  of  a 
particular  wheel.  This  is  often  true  in  gray  iron,  brass, 
steel  and  malleable  iron  foundries,  to  say  nothing  of  the 
innumerable  manufacturing  plants  where  a  diversity  of 
cylindrical  grinding  is  done. 

By  means  of  simple  appliances,  as  described  in  this 
chapter,  however,  it  is  possible  to  obtain  absolute  knowledge 
of  the  abrasive  efficiency  of  any  grinding  wheel  on  practically 
any  kind  of  material.  The  value  of  these  laboratory  tests 
should  not  be  under-estimated  as  they  give  the  efficiency 
engineer  knowledge  of  the  actual  worth  of  different  abra- 
sives and  different  makes  of  wheels  without  resorting  to  the 
production  department  for  data. 

On  cylindrical  grinding  especially,  owing  to  the  many 
factors  to  be  considered  while  testing  wheels  on  actual 
work,  such  as  depth  of  cut,  work  speed,  feed,  etc.,  it  is  a 
difficult  matter  sometimes  to  determine  which  is  the  better 
wheel  to  use.  Again,  operators  of  cylindrical  grinding 
machines  are  sometimes  unduly  prejudiced  in  favor  of  one 
particular  make  of  wheel,  often  flatly  refusing  to  be  con- 

"S 


ABRASIVES  AND  ABRASIVE  WHEELS 


vinced  that  other  grinding-wheel  manufacturers,  also,  make 
dependable  wheels.  Other  factors  also,  the  nature  of 
which  it  is  not  necessary  to  state  here,  sometimes  unduly 
influence  grinding-machine  operators,  or  even  department 
heads  to  whom  is  sometimes  left  the  selection  of  grinding 
wheels.  It  is  seen  that  laboratory  tests  can  be  relied  upon 
as  a  sure  means  to  the  desired  end;  that  is,  to  ascertain 
beyond  reasonable  doubt  the  actual  abrasive  efficiency  of 
all  wheels  offered  for  test  purposes. 

A  given  number  of  cubic  inches  of  abrasive  material 
incorporated  into  a  grinding  wheel  will,  at  a  given  surface 
speed,  remove  a  definite  amount  of  metal.  This  is  the 
hypostasis  upon  which  laboratory  tests,  to  determine  the 
abrasive  efficiency  of  grinding  wheels,  are  based. 

In  Fig.  26  is  illustrated  a  simple  testing  machine  for 
determining  the  efficiency  of  grinding  wheels  used  for  such 


Fig.  26. — Laboratory  grinding-wheel   testing   machine  for  testing   grinding 
wheels  used  in  hand-grinding  operations. 

purposes  as  grinding  castings  and  forgings,  general  grinding 
in  the  machine  shop,  tool  grinding,  or,  in  fact,  for  any  pur- 
pose where  the  work  is  held  in  contact  with  the  wheel  by 
hand. 

This  machine  consists  of  a  substantial  base   (A)  upon 
116 


LABORATORY  TESTS 

which  is  mounted  a  swing  frame  (B)  carrying  the  grinding 
wheel  (C).  The  pulley  (D)  on  the  jack  shaft  (E)  is  driven 
from  an  overhead  countershaft  of  the  variable-speed  type, 
while  the  pulley  (F)  on  the  wheel  spindle  (G)  is  driven  by 
the  pulley  (H). 

The  work  to  be  tested  is  shown  at  (J),  consisting  of  a 
bar  one  inch  square  held  in  the  anvil  (K)  by  means  of  a  set 
screw.  The  grinding  wheel  is  always  1 2  inches  in  diameter 
with  a  one-inch  face.  The  machine  should  be  very  rigid  to 
absorb  vibration,  for,  with  a  lightly  constructed  machine, 
vibration  is  sure  to  be  present,  which  would  cause  chatter- 
ing, thus  preventing  the  end  sought — to  determine  the 
efficiency  of  the  grinding  wheel  under  normal  conditions. 
The  wheel  spindle  is  2  inches  in  diameter  while  its  pulley 
is  6  inches  in  diameter  with  a  4-inch  face.  Both  pulleys 
on  the  jack  shaft  are  12  inches  in  diameter. 

Power  is  transmitted  by  means  of  three-inch  double-ply 
leather  belt.  The  object  of  the  ribs  on  the  swing  frame  and 
the  rib  on  the  base  is  to  make  the  construction  as  rigid  as 
possible  for  the  reason  previously  stated. 

The  swing  frame  should  be  counter- weighted  by  means  of 
a  weight  attached  to  a  cord  passing  over  over-head  pulleys. 
This  cord  is  fastened  to  the  rod  at  the  front  end  of  the  swing 
frame.  The  counter-weight  should  be  just  heavy  enough 
to  cause  the  grinding  wheel  to  exert  a  pressure  of  10  pounds 
on  the  work,  this  being  the  average  pressure  exerted  in 
hand-grinding  operations.  The  pressure  is  determined  by 
fastening  a  spring  balance  suspended  from  the  ceiling  to 
the  eye  on  the  swing  frame  directly  over  the  spindle. 

A  little  experimentation  with  a  machine  of  this  kind  is 
sure  to  disclose  startling  results  regarding  the  efficiency 
of  different  grinding  wheels.  Some  wheels  will  be  found  to 
cut  readily,  holding  their  shape  well,  while  others  prove  to 
be  comparatively  slow  cutting.  The  wheels  should  all  be 
run  at  the  same  speed,  1,592  R.  P.  M.  being  the  correct 
speed  for  a  1 2-inch  wheel,  the  above  number  of  revolutions 
per  minute  giving  a  peripheral  speed  of  5,000  feet  per 

117 


ABRASIVES  AND  ABRASIVE  WHEELS 


minute,  which  surface  speed  is  considered  correct  for  hand- 
grinding  operations.  If  the  speed  is  retained  constant  at 
1,592  R.  P.  M.  and  the  same  pressure  exerted  in  all  tests 
(10  pounds)  it  follows  that  all  wheels  tried  are  given  a  fair 
and  impartial  test  since  they  are  tried  under  the  same  con- 
ditions. 

The  test  bar  should,  of  course,  be  made  of  the  same  ma- 
terial on  which  the  grinding  wheel  is  used  on  actual  pro- 
duction work.  The  wheel,  after  being  carefully  weighed, 
is  placed  in  position  on  the  spindle  and  carefully  trued  by 
means  of  the  dresser  shown  in  Fig.  27,  which  consists  of  a 


r-\rv 

So| 

:Rfff]tf 
-j{tj|jl 

-LH_HJ-L 


Fig.  27. — Star-wheel  dresser  for  use  with  testing  machine. 

few  star-wheel  cutters  mounted  in  a  holder  which  fits  the 
hole  in  the  anvil.  The  test  bar  is  now  placed  in  position 
and  the  test  conducted  for  one  half -hour.  At  the  expiration 
of  this  period,  the  number  of  cubic  inches  of  material  ground 
away  are  noted  and  the  wheel  taken  off  and  weighed  to 
determine  the  weight  of  abrasive  material  used.  This  should 
be  done  on  a  sensitive  scale  which  accurately  registers 
ounces. 

It  is  evident  that  the  wheel  which  will  grind  away  the 
greatest  amount  of  material  in  a  given  time,  with  the  least 
amount  of  loss  to  the  wheel  itself,  is  the  most  efficient 
wheel  to  use  for  the  purpose  in  question.  In  ordering 
wheels  for  test  purposes  on  a  machine  of  this  kind,  it  is 

118 


LABORATORY  TESTS 

best  to  get  at  least  two  from  each  maker.  The  performance 
of  each  wheel  should  be  carefully  noted  and  in  comparing 
wheels  of  different  makes,  the  most  efficient  of  each  is 
considered.  The  records  of  all  tests  conducted  should  be 
kept  in  a  book  provided  for  the  purpose  and,  after  a  few 
weeks  of  experimenting  the  manufacturer  should  have  at 
his  disposal  authentic  data  relating  to  the  performance  of 
many  wheels.  The  records  should  be  kept  on  a  form  like 
the  following: 

Make  of  wheel, 

Cost, 

Grit, 

Grade, 

Bond, 

Diameter, 

Face, 

Weight, 

Cost  per  lb., 

Material  tested, 

Grinding  pressure, 

Wheel  speed, 

Length  of  test, 

Weight  of  wheel  after  test, 

Wheel  loss, 

Cubic  inches  of  material  removed, 

Grinding  cost  per  cubic  inch. 

Remarks. 

It  is  readily  seen  that  it  is  a  more  simple  matter  to  de- 
termine the  abrasive  efficiency  of  a  grinding  wheel  on  a 
machine  of  the  above  kind  than  it  is  to  conduct  a  long  test 
in  the  shop.  Again,  the  results  derived  from  these  tests 
can  be  relied  upon  as  the  testing  can  be  done  under  the 
direct  supervision  of  the  efficiency  engineer,  who  cannot 
always  spare  the  time  personally  to  superintend  a  long 
test  on  actual  work  in  the  production  department. 

The  machine  shown  in  Fig.  28  is  designed  to  test  wheels 
as  used  for  cylindrical  grinding.  It  consists  of  a  solid  base 
(A)  carrying  a  wheel  spindle  (B)  on  which  is  mounted  a 
wheel  12  inches  in  diameter  with  a  i-inch  face  and  5 -inch 

119 


ABRASIVES  AND  ABRASIVE  WHEELS 


Fig.  28. — Laboratory  grinding-wheel  testing  machine  for  testing  grinding 
wheels  used  in  cylindrical  grinding  operations. 


LABORATORY  TESTS 

hole.  This  wheel  is  a  regular  stock  size  as  it  fits  several 
cylindrical  grinding  machines. 

The  piece  to  be  tested  consists  of  a  disc  (C)  2  inches  in 
diameter,  i  inch  wide  with  a  3/4-inch  hole.  It  is  made  of 
the  material  upon  which  it  is  desired  to  test  the  wheel  and 
is  fastened  in  place  on  the  work  spindle  (D)  by  means  of  the 
nut  (E)  which  holds  the  piece  against  a  shoulder  on  the 
work  spindle.  The  work  spindle  is  mounted  on  the  swing 
frame  (F). 

The  work  is  kept  in  contact  with  the  wheel  by  means  of 
the  weight  (G)  on  the  lever  (H).  The  weight  is  adjusted 
to  make  the  wheel  spark  heavily  as  it  does  on  regular  pro- 
duction work  when  working  at  its  maximum  limit.  The 
same  amount  of  pressure  should  be  used  in  testing  all  wheels 
otherwise  a  fair  decision  is  not  possible. 

A  diamond  mounted  in  the  holder  (J)  which  fits  the  slide 
(K)  at  the  back  of  the  machine  is  for  the  purpose  of  truing 
the  wheel.  The  testing  can  be  done  either  wet  or  dry.  The 
machine  shown  is  designed  for  dry  testing,  but  with  the 
addition  of  a  hood  to  cover  the  wheel  and  a  pipe  to  supply 
water  at  the  point  of  grinding  contact,  tests  in  wet  grinding 
can  be  conducted. 

The  tests  are  carried  on  in  the  same  manner  as  those  just 
described  with  a  view  to  determining  which  is  the  fastest 
cutting  wheel  with  the  least  amount  of  wear.  As  previously 
stated,  it  is  often  a  difficult  matter  to  determine  the  actual 
efficiency  of  a  wheel  used  for  cylindrical  grinding  owing  to 
the  many  factors  to  be  considered.  With  a  machine  of  this 
kind  for  conducting  comparative  tests,  however,  wherein 
the  factors  are  simplified  as  much  as  possible,  tangible 
results  are  possible  in  a  very  short  time  without  the  neces- 
sity of  interrupting  the  regular  work  in  the  grinding  de- 
partment. 

The  manufacturer  who  wishes  to  reduce  his  grinding  costs 
will  do  well  to  conduct  a  few  simple  tests  as  outlined  in  this 
and  the  previous  chapter.  The  results  of  the  tests  should  be 
carefully  noted  for  future  reference,  and  by  testing  different 


ABRASIVES  AND  ABRASIVE  WHEELS 

makes  of  wheels  and  different  grits  and  grades  of  the  same 
make,  economical  results  in  the  production  department  are 
sure  to  follow.  It  costs  comparatively  little  to  test  grinding 
wheels  when  the  work  is  undertaken  in  the  right  way  and 
the  actual  saving  in  dollars  and  cents  that  results  from 
reliable  tests  makes  it  worth  while  to  conduct  them. 


CHAPTER  EIGHT 

GRINDING   WHEEL  VS.   GRINDSTONES 

Advantages  of  natural  and  artificial  abrasive  used  in  wheels — Early  use  of 
grindstones — Special  work  where  grindstones  are  still  employed — Action 
of  grinding  wheel. 

AS  previously  stated  in  another  chapter,  the  grindstone 
•**•  is  the  oldest  form  of  grinding  wheel  known,  being  at 
one  time  exclusively  used  for  all  grinding  operations.  When 
the  grinding  wheel  made  of  emery  was  first  put  on  the 
market,  some  forty  years  ago,  it  did  not  readily  meet  with 
favor  in  the  manufacturing  world  owing  to  many  dis- 
advantages. In  the  first-  place  it  was  often  dangerous; 
being  liable  to  burst  from  centrifugal  strain  without  a  mo- 
ment's notice  and,  again,  the  high  speed  at  which  it  was  run, 
together  with  the  low  abrasive  efficiency  of  the  grinding 
material  used,  caused  it  to  draw  the  temper  of  edge  tools 
unless  great  care  was  exercised  in  the  grinding  operation. 
The  grinding-wheel  industry  of  today  being  in  its  infancy, 
grinding-wheel  manufacturers  faced  a  serious  problem  in 
finding  a  market  for  their  goods. 

While  the  old-fashioned  emery  wheel  of  previous  days 
did  not  successfully  compete  with  the  grindstone,  in  the 
edge  tool,  saw,  file  and  other  industries  it  began  to  be  used 
for  many  operations  heretofore  accomplished  by  the  slow 
hand  method  of  filing.  As  a  matter  of  fact,  it  was  common 
practice  to  file  all  kinds  of  castings  as  late  as  twenty-five 
years  ago,  but  as  experience  proved  that  the  emery  wheel 
furnished  a  more  rapid  means,  together  with  the  fact  that 
emery-wheel  manufacturers  began  to  seriously  consider  the 
factor  of  safety,  the  grinding  wheel  slowly  advanced  in 

123 


ABRASIVES  AND  ABRASIVE  WHEELS 

favor.  In  the  year  1878,  Mr.  Hart  of  Detroit  obtained  a 
novel  patent  on  a  grinding  wheel  containing  a  wire  web, 
the  object  of  which  was  to  prevent  the  fragments  of  the 
wheel  from  flying  in  case  it  burst.  This  was  readily  ac- 
cepted as  a  great  improvement,  which  indeed  it  was,  and 
the  grinding-wheel  business  thereby  received  a  remarkable 
impetus. 

With  the  general  introduction  of  corundum  in  the  early 
•eighties,  grinding  wheels  began  to  be  used  for  other  pur- 
poses aside  from  rough  grinding  owing  to  the  fact  that 
a  cooler  cutting  wheel  could  be  made  by  substituting 
•corundum  for  emery.  Thus  corundum  wheels  found  a 
limited  market  for  certain  tool-grinding  operations  hitherto 
done  on  the  grindstone. 

With  the  adoption  of  cylindrical  grinding  machines  for 
finishing  hardened  parts  of  machinery,  the  grinding-wheel 
business  was  established  on  a  firm  basis  owing  to  the  fact 
that  the  cylindrical  grinder  furnished  a  sole  means  for  a 
desired  end;  that  is,  doing  work  that  could  not  be  done 
•either  with  the  file  or  grindstone.  With  the  improvement 
of  cylindrical  and  other  precision-grinding  machinery,  the 
grinding-wheel  industry  has  kept  pace;  abrasive  wheels 
being  used  at  the  present  day  for  thousands  of  manufacturing 
operations. 

Strange  as  it  may  seem,  however,  the  modern  grinding 
wheel  has  not  wholly  replaced  the  grindstone  for  certain 
operations  owing  chiefly  to  the  cheapness  of  grindstones 
and  to  the  manner  in  which  they  act  on  the  work  with  which 
they  are  brought  in  contact. 

A  grindstone  is  run  at  a  comparatively  slow  peripheral 
speed,  so  slow  that  it  will  not  throw  water  from  its  surface. 
In  the  grinding  operation,  particles  of  quartz  are  torn  from 
the  stone  and  these  floating  in  the  surface  water  present  a 
planing  action  on  the  work,  often  with  a  shearing  cut  as 
the  particles  of  quartz  are  dragged  under  the  piece  being 
.ground.  Any  mechanic  realizes  that  a  shearing  cut  is  very 
•effective  and  this  peculiarity  of  "grindstone  action,"  as  it 

124 


GRINDING  WHEEL  VS.   GRINDSTONES 

is  termed,  together  with  the  fact  that  quartz  in  itself  is  a 
very  efficient  abrasive  for  some  classes  of  work,  accounts 
for  the  fact  that  the  old  grindstone  is  still  in  favor  in  cer- 
tain phases  of  work. 

At  the  present  day,  grindstones  are  used  for  a  number  of 
surfacing  operations  such  as  grinding  the  sides  of  saws, 
grinding  file  blanks,  surfacing  plows,  axe  grinding,  etc. 
Large  numbers  of  grindstones  called  pulp  stones  are  used 
in  preparing  wood  pulp  for  paper  manufacturers.  In  this 
particular  field,  the  grinding  wheel  cannot,  or,  at  least,  has 
not  been  able  to  compete  successfully  owing  to  the  low  initial 
cost  of  grindstones  and  to  the  fact  that  grinding  wheels 
do  not  prepare  the  material  in%the  desired  manner  to  suit 
American  paper  manufacturers.  In  the  Scandinavian  coun- 
tries, however,  a  special  form  of  manufactured  grinding 
wheel  is  used  for  pulp  grinding,  but  these  same  wheels 
do  not  find  favor  in  this  country. 

In  the  manufacture  of  files,  •  the  grindstone  is  still  used 
in  large  quantities  owing  to  the  fact  that  it  leaves  just  the 
proper  kind  of  surface  for  the  tools  that  cut  the  file  teeth. 
Numerous  experiments  have  been  tried  to  develop  a 
grinding  wheel  to  do  this  class  of  work  successfully,  but  to 
the  best  of  the  writer's  knowledge  no  success  has  been 
attained. 

That  the  grindstone  still  shows  efficiency  on  certain 
classes  of  work  cannot  be  doubted  and  as  an  illustration 
of  this  we  can  consider  the  subject  of  axe  grinding.  As  they 
come  to  the  grinding  room,  axes,  like  other  products  of 
the  forge,  are  in  a  rough  state  and  the  operation  of  grinding 
them  smooth  before  they  are  tempered  is  termed  by  the 
axe  manufacturer  "press  grinding"  or  "pressing."  A  press 
in  this  case  is  nothing  more  or  less  than  a  stout  iron  bar 
to  hold  the  axe  firmly  against  the  stone,  pressure  being  ap- 
plied by  means  of  a  foot-operated  treadle. 

The  stones  used  for  this  work  are  six  feet  in  diameter 
and  twelve  inches  thick,  costing  at  a  fair  market  price, 
$25.00  each.  One  of  these  stones  lasts  approximately  three 

125 


ABRASIVES  AND  ABRASIVE  WHEELS 

weeks,  during  which  time  it  grinds  3,500  axes.  Considering 
ten  hours  as  a  day's  work,  it  is  seen  that  the  operation 
of  rough  grinding  one  axe  consumes  three  minutes.  Now 
there  are  a  good  many  square  inches  on  the  surface  of  an 
axe  and  any  abrasive  whatsoever  that  will  do  this  work 
in  the  short  time  of  three  minutes  is  efficient  to  say  the 
least.  The  cost  of  abrasive  material  used  per  axe  is  less 
than  one  cent,  being  approximately  7/10  of  a  cent. 

If  we  invest  our  $25.00  in  a  grinding  wheel  we  can,  at  a 
fair  market  price,  purchase  a  wheel  30  inches  in  diameter 
with  a  2-1/2 -inch  face,  one  24  inches  in  diameter  with  a 
3-1 /2-inch  face,  or  one  20  inches  in  diameter  with  a  5-1/4- 
inch  face.  A  grindstone  6  feet  in  diameter  with  a  12 -inch 
face,  contains  48,858  cubic  inches,  whereas  a  typical  grinding 
wheel  that  can  be  purchased  for  the  same  price,  a  30  x  2-1/2 
for  an  illustration,  contains  but  1,767  cubic  inches.  Thus 
it  is  seen  that  a  decided  factor  is  in  favor  of  the  grindstone ; 
that  is,  its  low  cost  per  cubic  inch.  It  naturally  follows 
that  a  grinding  wheel  to  compete  with  a  grindstone  on  the 
work  in  question  must  be  highly  efficient  owing  to  the  fact 
that  its  cost  per  cubic  inch  is  much  greater.  Again  we 
must  not  lose  sight  of  the  fact  that  it  takes  a  very  fast- 
cutting  grinding  wheel  to  surface  an  axe  in  three  minutes. 

However,  notwithstanding  that  grindstones  are  cheap 
and  efficient,  the  grinding  wheel  is  gradually  creeping  into 
the  axe  industry,  owing  to  the  fact  that  its  adoption  offers 
advantages  that  cannot  be  had  while  using  grindstones. 
A  prominent  axe  manufacturer  with  whom  the  writer  has 
had  some  recent  correspondence  regarding  the  grinding 
wheel  in  the  axe  factory,  has  the  following  to  say  in  favor 
of  the  grinding  wheel. 

"Our  general  opinion  is  that  grinding- wheel  grinding  is 
as  economical  in  labor  cost  and  abrasive  cost  as  wet-stone 
grinding,  but  the  collateral  advantages  of  the  grinding- 
wheel  grinding  throw  the  advantages  strongly  in  favor  of 
this  method.  Grinding-wheel  grinding  takes  up  much  less 
space,  requires  less  power  and  permits  better  working  con- 

126 


GRINDING  WHEEL  VS.   GRINDSTONES 

ditions  because  the  grinding  wheels  can  be  used  with  ex- 
haust hoods  to  carry  off  the  dust,  and  even  if  they  are  used 
wet  the  water  can  be  confined;  whereas  with  wet  grinding 
with  large  grindstones,  the  men  are  constantly  wet  and  the 
department  cannot  be  kept  either  clean  or  sanitary." 

Abrasive  engineers  and  grinding- wheel  .salesmen  are  prone 
to  discuss  the  possibilities  of  the  grinding  wheel  wholly 
replacing  the  grindstone  in  various  manufacturing  pursuits. 
As  a  matter  of  fact,  the  above  theme  has  been  discussed 
more  or  less  ever  since  the  grinding  wheel  first  made  its 
appearance  nearly  fifty  years  ago.  Notwithstanding  that 
the  grindstone  is  entirely  different  in  grinding  action  from 
the  grinding  wheel,  the  latter  is  slowly  gaining  in  favor 
owing  to  the  rapid  strides  made  in  abrasive  engineering, 
and  in  considering  future  possibilities  in  fields  now  oc- 
cupied by  the  grindstone,  we  are  confronted  with  two 
vital  factors. 

First,  the  grindstone  is  a  natural  product;  thus  it  cannot 
be  altered — it  must  be  accepted  just  as  nature  formed  it, 
millions  of  years  ago  when  the  earth  was  young.  Different 
degrees  of  hardness  and  variations  of  the  size  of  the  quartz 
grain  of  which  the  stone  is  composed  can  be  had,  to  be  sure, 
but  neither  the  abrasive  itself,  nor  the  natural  bonding  ma- 
terial that  holds  the  innumerable  grains  of  which  the 
grindstone  is  composed  can  be  changed  by  the  arts  of 
man. 

Second,  the  grinding  wheel  can  be  made  to  differ  in  quite 
a  number  of  ways  to  suit  varied  grinding  conditions.  It 
Can  be  composed  of  various  kinds  of  abrasives  bonded 
together  by  many  different  means.  Again,  it  can  be  coarse 
or  fine,  hard  or  soft,  compact  or  open,  brittle  or  tough.  In 
fact  the  abrasive  engineer  of  the  present  time  first  studies 
the  work  to  be  performed  and  then  makes  a  wheel  to  suit 
the  requirements,  and  in  cases,  where  the  experimental 
wheel  fails  to  come  up  to  his  expectations,  he  profits  by  the 
failure  and  tries  again. 

By  this  method,  and  this  method  only,  the  grinding 
127 


ABRASIVES  AND  ABRASIVE  WHEELS 

wheel  has  been  adapted  to  purposes  undreamed  of  a  few 
years  ago,  comparatively  speaking,  thus  it  is  reasonable  to 
assume  that  the  knowledge  of  future  years  will  produce  a 
grinding  wheel  that  will  eventually  replace  the  grindstone 
just  as  artificial  abrasives  have  practically  replaced  the 
emery  wheel  of  yesterday. 


CHAPTER   NINE 

THE    ECONOMIC   ADVANTAGE   OF   USING    LARGE   WHEELS 

Factors  to  be  considered  in  choosing  a  wheel — Comparative  price  of  wheels 
of  various  sizes — Advantage  of  large  wheels  in  certain  work — Why  large 
wheels  are  more  efficient. 

'T'HOSE  who  purchase  grinding  wheels  have  probably 
*•  noticed  that  the  grinding- wheel  salesman  seems  anxious 
to  sell  large  wheels^  that  is  16  x  2  inches  or  over.  This  is 
not  always  because  the  salesman  wishes  to  write  up  a 
"nice  order,"  as  it  were.  Contrary  to  this,  he  generally 
has  his  customer's  interests  in  mind  and  realizes  that  there 
is  true  economy  in  using  comparatively  large  wheels,  as  the 
following  figures  show.  The  wheel  sizes  and  list  prices 
are  taken  from  the  standard  grinding-wheel  list  and  a 
perusal  of  the  same  shows  that  the  cost  of  grinding  wheels, 
per  cubic  inch,  in  most  instances,  decreases  as  the  size 
increases. 

There  are  some  exceptions  to  this  rule,  however,  for,  as 
the  data  shows,  a  24  x  4-inch  wheel  costs  more  per  cubic 
inch  than  a  20  x  3 -inch  wheel.  It  is  well  for  the  purchasing 
agent  who  wishes  to  buy  as  economically  as  possible  to 
figure  carefully  the  cost  per  cubic  inch  of  the  various-sized 
wheels  that  he  buys  to  ascertain  whether  or  not  he  is  buy- 
ing to  advantage. 

The  greatest  difference  in  cost  per  cubic  inch  is  found 
in  wheels  below  20  inches  in  diameter.  With  wheels  larger 
than  this  the  cost  difference  per  cubic  inch  is  not  so  great, 
and  in  some  instances  there  is  no  decrease  in  cost  per  cubic 
inch  with  an  increase  of  size.  As  an  illustration,  a  30  x  4- 
inch  wheel  costs  just  as  much  per  cubic  inch  as  a  20  x  3 -inch 

129 


ABRASIVES  AND  ABRASIVE  WHEELS 

wheel,  while  the  cost  per  cubic  inch  of  a  60  x  8 -inch  wheel 
is  only  slightly  less  than  that  of  a  30  x  4-inch  wheel. 

Size 10  x  1-1/2 

List  price $10.20 

Area  in  cubic  inches 117.81 

Cost  per  cubic  inch $00.0871 

Cost  per  hundred  cubic  inches $8.71 

Size 12x2 

List  price $16.70 

Area  in  cubic  inches 226.20 

Cost  per  cubic  inch $00.0738 

Cost  per  hundred  cubic  inches $7.38 

Size 16  x  2-1/2 

List  price $3 2.40 

Area  in  cubic  inches 502.65 

Cost  per  cubic  inch $00.0645 

Cost  per  hundred  cubic  inches $6.45 

Size 20  x  3 

List  price $58.00 

Area  in  cubic  inches 942.48 

Cost  per  cubic  inch $00.0615 

Cost  per  hundred  cubic  inches $6.15 

Size 24  x  4 

List  price $i  13.00 

Area  in  cubic  inches 1,809.56 

Cost  per  cubic  inch $00.0624 

Cost  per  hundred  cubic  inches $6.24 

Size 30  x  4 

List  price $174.00 

Area  in  cubic  inches 2,827.44 

Cost  per  cubic  inch $00.0615 

Cost  per  hundred  cubic  inches $6.15 

Size : '. 60  x  8 

List  price $1,358 

Area  in  cubic  inches. . 22,619.20 

Cost  per  cubic  inch $00.060 

Cost  per  hundred  cubic  inches $6.00 

The  advantage  of  using  comparatively  large  wheels  is 
shown  in  the  following  comparison :  Let  it  be  assumed  that 
a  concern  uses  two  hundred  12  x  2-inch  grinding  wheels 

130 


ECONOMIC  ADVANTAGE  OF  USING  LARGE  WHEELS 

annually.  At  a  fair  market  price  these  wheels  would  cost 
$835.00.  The  two  hundred  wheels  contain  45,240  cubic 
inches,  and  in  using  them  until  they  are  four  inches  in 
diameter,  40,214  cubic  inches  of  material  are  actually  used 
while  5,026  cubic  inches  are  discarded  in  the  stubs,  which 
represent  an  actual  cost  of  $92.47. 

If  24  x  4-inch  wheels  were  used  in  place  of  the  12  x  2 -inch 
wheels,  twenty-five  will  contain  45,239  cubic  inches  which 
is  practically  the  cubical  contents  in  inches  of  the  two 
hundred  12  x  2 -inch  wheels.  Twenty-five  24  x  4-inch  wheels, 
bought  at  the  same  discount  that  applied  to  the  12  x  2 -inch 
wheels,  would  cost  $706.25.  In  using  the  wheels  to  a 
diameter  of  8  inches,  practically  the  same  amount  of  abra- 
sive material  is  used  as  heretofore,  that  is  40,213  cubic 
inches,  and  in  comparing  the  two  prices  it  is  seen  that  there 
is  an  actual  saving  of  $128.75.  The  twenty-five  8  x  4-inch 
stubs  contain  5,026  cubie  inches  and  represent  an  invest- 
ment of  $70.40  against  $92.47,  the  cost  of  the  stubs  of  the 
12  x  2-inch  wheels.  Thus  another  saving,  amounting  to 
$14.07  is  effected. 

Another  point  that  should  not  be  overlooked  In  consider- 
ing large  wheels  is  that  a  pair  of  comparatively  large  wheels 
mounted  on  a  heavy  grinding  stand  are  more  free  from 
vibration  than  small  wheels  mounted  on  light  stands. 

If  we  take  an  ordinary  machinist's  hammer  and  beat  a 
piece  of  steel  with  it  for  a  few  seconds,  the  face  of  the 
anvil,  for  instance,  both  the  hammer  and  the  anvil  become 
slightly  heated,  owing  to  the  fact  that  the  energy  of  the 
blows  has  been  transformed  into  heat.  Consider  for  a 
moment  the  wasted  energy  expended  by  a  vibrating  grinding 
wheel  traveling  at  a  peripheral  speed  of  5,000  feet  per 
minute.  Here  the  same  principle  above  explained  holds 
true  even  if  the  grinding  wheel  vibrated  but  very  little. 

A  grinding  wheel  should  generate  as  little  heat  as  possible; 
the  wheel  that  vibrates  while  in  use  is  very  inefficient 
because  some  of  the  energy  that  should  be  expended  in 
removing  metal  is  used  in  generating  useless  heat. 


ABRASIVES  AND  ABRASIVE  WHEELS 

As  the  surface  of  a  grinding  wheel  presents  thousands 
of  cutting  points  to  the  work,  it  is  evident  that  the  surface 
having  the  most  points  to  present  to  a  given  piece  of  work 
will  last  the  longest  without  becoming  dulled,  or  glazed. 
In  considering  a  14  x  2-inch  wheel  in  20  grit,  we  have  a 
cutting  surface  of  87.9648  square  inches  and  allowing  400 
cutting  points  to  the  square  inch  the  sum  of  these  equals 
35,185.  On  the  other  hand,  a  2 4  x  3  -inch  wheel  has  a  cutting 
surface  of  226.1952  square  inches  containing  90,478  cutting 
points.  It  is  plainly  seen  that  the  latter  is  bound  to  remain 
in  cutting  condition  longer  than  the  former. 

Why  is  it  then,  that  many  manufacturers  persist  in  using 
comparatively  small  grinding  wheels  mounted  on  light 
stands?  In  the  first  place,  small  grinding-wheel  stands  are 
cheap  to  install  and  the  wheels  for  the  same  are  not  an 
expensive  item  when  bought  a  few  at  a  time.  There  is,  of 
course,  a  place  for  the  small  grinding  wheel,  but  for  the 
average  jrun  of  general  work,  snagging  castings  and  forgings, 
tool  grinding,  etc.,  it  is  false  economy  to  use  wheels  smaller 
than  20  inches  in  diameter.  An  ideal  size  to  use  for  any 
of  the  above  purposes  is  30x4  inches,  but  outside  of  the 
plow  industry,  this  size  is  little  used.  The  cheapest 
course  in  the  long  run  is  to  consign  the  small  grinding-wheel 
stands  to  the  scrap  heap  and  install  larger  ones;  and  in 
the  meanwhile  the  consumer  of  grinding  wheels  should  be 
educated  to  the  fact  that  small  wheels  are  expensive  at  any 
price. 


CHAPTER  TEN 

TRUING    DEVICES    FOR   GRINDING   WHEELS 

(Reprinted  from   The  Iron  Age.) 

Abrasive  action  —  Tools  used  in  truing  wheels  —  Use  of  bort  and  carbonado 
diamonds  in  tools  —  Getting  stones  in  tool  —  Procedure  in  truing  wheels. 


RINDING  wheels  are  in  reality  cutting  tools  re- 
volving  at  high  speed  whereby  countless  sharp  points 
remove  minute  chips  by  what  we  call,  for  want  of  a  better 
term,  the  action  of  abrasion.  In  the  strictest  sense  of  the 
word,  this  is  not  correct  because  the  word  abrasion  means 
to  wear  or  rub,  whereas  a  modern  grinding  wheel  actually 
removes  material,  be  it  hard  or  soft,  by  a  cutting  instead 
of  a  wearing  action.  To  obtain  the  best  results,  the  in- 
numerable cutting  points  on  the  surface  of  the  wheel  should 
be  kept  sharp  and  the  periphery  concentric  with  the  spindle  ; 
otherwise  the  efficiency  of  the  wheel  is  materially  lowered. 
In  this  chapter,  a  few  simple  methods  for  truing  grinding 
wheels  will  be  briefly  considered. 

The  tools  used  for  this  purpose  are  of  two  kinds,  diamonds 
and  ordinary  emery-wheel  dressers.  There  are  two  varieties 
of  diamonds  used,  that  is  to  say  bort  stones,  many  of 
which  are  nearly  white  in  color,  and  a  black  variety  called 
carbonado  or  black  diamond.  Bort  stones  are  compara- 
tively inexpensive  when  compared  with  black  diamonds, 
but  they  are  not  so  hard  and  consequently  are  shorter  lived. 
It  is,  therefore,  more  economical  to  use  black  diamonds. 
Both  varieties  are  sold  by  the  carat  and  can  be  bought  loose 
or  already  mounted  in  steel  or  copper  holders.  The  majority 
of  manufacturers  prefer  to  buy  loose  stones,  as  by  this 
method  flaws  are  more  readily  detected,  and  since  the  stones 


ABRASIVES  AND  ABRASIVE  WHEELS 


are  never  guaranteed  it  is  important  to  see  that  only  good 
specimens  are  selected. 

The  operation  of  setting  the  stones  is  comparatively 
simple  and  can  be  intrusted  to  any  tool  maker  who  has  the 
reputation  of  being  a  careful  workman.  In  setting  a  stone, 
all  workmen  do  not  proceed  along  the  same  lines,  but  the 
following  method,  which  is  used  by  many  tool  makers,  is 
simple  and  satisfactory.  First,  select  a  drill  of  the  same 
size  as  the  stone.  This  is  readily  accomplished  by  passing 
the  stone  through  the  holes  in  an  ordinary  drill  gauge.  As 
stated  before,  both  steel  and  copper  holders  are  used,  but 
in  actual  practice  the  latter  makes  the  better  holder  for 
two  reasons.  First,  it  is  very  malleable  and  thus  is  easily 
worked,  and  also  copper  is  an  excellent  conductor  of  heat 
and  readily  absorbs  superfluous  heat,  thereby  tending  to 


m 


Fig.  29.— First  step  in  mounting  the  diamond. 

Fig.  30. — The  metal  in  position  over  the  stone. 

Fig.  31. — The  finished  setting  with  the  superfluous  metal  removed. 

Fig.  32. — Special  type  of  diamond  holder. 

prevent  overheating  the  stone,  which  sometimes  causes  it  to 
fracture.  The  rod  should  be  about  six  inches  long  and  of 
the  correct  diameter  to  fit  the  holder  of  the  machine  where 
it  is  to  be  used.  A  hole  is  drilled  in  the  end  of  the  rod 
deep  enough  to  bury  the  stone,  as  shown  in  Fig.  29.  The 
next  step  is  to  force  over  the  metal  over  the  edges  of  the 
stone  firmly  in  place.  This  ±s  done  with  a  light  hammer 
and  a  small  staking  chisel,  The  result  is  shown  in  Fig.  30. 

i34 


TRUING  DEVICES  FOR  GRINDING  WHEELS 

Care  should  be  exercised  as  a  diamond  is  quite  brittle  and 
easily  broken  by  a  chance  blow.  The  completed  setting 
is  shown  in  Fig.  31,  the  superfluous  metal  having  been 
turned  away.  Some  tool  makers  prefer  to  braze  the  stone 
in  position,  and  while  this  method  no  doubt  holds  the  stone 
firmly  in  place,  the  heat  necessary  to  melt  the  spelter  is 
liable  to  crack  the  stone.  However,  as  the  method  of  braz- 
ing stones  in  place  is  often  used  by  reliable  manufacturers 
there  certainly  is  some  authority  for  employing  it.  The 
process  consists  of  filling  the  hole  about  half  full  of  spelter 
and  flux,  and  when  this  has  reached  a  molten  state,  the 
stone  is  pressed  in  place,  which  causes  the  spelter  to  rise 
in  the  hole,  thus  forming  a  matrix  that  grips  the  stone 
firmly.  "  It  may  be  well  to  add  that  the  work  should  under 
no  circumstances  be  cooled  in  water,  as  the  sudden  contrac- 
tion of  the  diamond  will  in  many  cases  cause  it  to  fracture. 

Even  the  hardest  stones  will  wear  flat  in  time.  It  is' 
necessary  to  reset  them  occasionally,  which  brings  a  new 
cutting  edge  in  position.  This  is  done  by  turning  the  stone 
upside  down  or  canting  it  sideways.  The  holder  shown  in 
Fig.  32  accomplishes  this  in  a  very  simple  manner.  It 
consists  of  an  auxiliary  plug  in  which  the  stone  is  mounted, 
fitting  a  hole,  the  axis  of  which  is  at  a  slight  angle  with  that 
of  the  main  holder.  The  plug  is  held  in  place  by  means  of 
a  set  screw.  When  the  stone  becomes  flattened,  the  plug 
is  turned  slightly,  which  brings  a  new  cutting  edge  in  posi- 
tion. This  device  is  covered  by  patent  and  it  is  not  public 
property. 

Care  should  be  exercised  while  using  a  diamond  as  an 
undue  strain  caused  by  gouging  it  into  the  wheel  often  re- 
sults in  tearing  the  stone  from  its  setting,  in  which  event 
it  is  generally  lost.  In  truing  wheels  on  cylindrical  grinding 
machines,  water  should  always  be  used  to  keep  down  fric- 
tional  heat  and  several  light  cuts  are  to  be  preferred  to  a 
few  heavy  ones.  It  is  hardly  necessary  to  state  that  the 
tool  should  never  be  guided  by  hand  as  it  is  impossible 
to  do  a  satisfactory  job  in  this  manner.  Nearly  all  grinding 

135 


ABRASIVES  AND  ABRASIVE  WHEELS 

machines  are  equipped  with  suitable  holders  to  accommodate 
truing  devices  and  they  should  always  be  used. 

The  device  illustrated  in  Fig.  33  is  excellent  for  truing 
wheels    used    on    surface-grinding    machines.      It    is    very 


Fig-  33- — Simple  device  for  truing  wheels  on  surface  grinders. 

simple,  consisting  of  a  diamond  set  in  a  holder  1-1/2  inches 
long,  which  is  fastened  in  a  block  of  cast  iron  by  means  of 
a  set  screw.  It  can  be  used  on.  a  magnetic  chuck  or  clamped 


Fig.  34. — Device  for  truing  wheels  on  cutter  grinding  machines. 


in  a  vise.     For  truing  wheels  on  various  types  of  cutter- 
grinding  machines,   an  angle  iron,   as  shown  in  Fig.    ^54, 
.   136 


TRUING  DEVICES  FOR  GRINDING  WHEELS 

gives  good  results.  The  diamond  holder  is  fastened  by 
means  of  a  set  screw  and  the  angle  iron  is  clamped  to  the 
platen  of  the  machine  by  a  strap,  bolt,  or  other  convenient 
means. 

We  are  sometimes  inclined  to  look  askance  at  ordinary 
emery-wheel  dressers  in  connection  with  wheels  for  precision 


Fig-  35- — Grinding- wheel  dressers  mounted  in  a  special  holder  for  truing 
wheels  used  on  cylindrical  grinding  machines. 

grinding,  but  under  certain  limited  conditions  they  are 
productive  of  excellent  results.  In  ordinary  cylindrical 
grinding,  it  is  customary  to  rough  out  several  hundred 
pieces  before  taking  any  finishing  cuts,  and  as  we  are  re- 


Fig.  36. — Truing  device  for  use  on  large  vertical  spindle  grinding  machines. 

moving  stock  only,  paying  absolutely  no  attention  to  finish, 
.all  that  we  desire  is  a  fast-cutting  wheel.  In  cases  of  this 
kind,  a  few  emery-wheel  dresser  cutters  mounted  in  a 
holder,  as  shown  in  Fig.  35;  will  prove  a  revelation  to  the 


ABRASIVES  AND  ABRASIVE  WHEELS 

man  who  has  never  used  them.  They  keep  the  wheel  rough 
and  free  cutting,  which  is  just  the  condition  required. 

For  truing  the  wheels  used  on  large  vertical  spindle 
surface-grinding  machines,  a  holder,  as  shown  in  Fig.  36, 
will  be  found  a  valuable  accessory.  It  should  be  provided 
with  slots  for  clamping  it  in  place.  On  the  magnetic  chuck, 
however,  the  force  of  the  magnetism  is  sufficient  to  keep 
the  holder  in  place. 

It  must  be  borne  in  mind  that  emery-wheel  dressers 
are  practicable  for  roughing  wheels  only,  but  when  we 
stop  to  consider  that  even  a  comparatively  small  diamond 
costs  several  dollars,  whereas  a  set  of  emery-wheel  dressers 
can  be  purchased  for  a  few  cents,  their  merits  are  well  worth 
consideration. 


CHAPTER  ELEVEN 

RE-BUSHING    GRINDING   WHEELS 

(Reprinted  from  Canadian  Machinery.) 

Methods  used  in  bushing  wheels — Tools  employed — Metals  used. 

MANY  large  manufacturing  concerns  use  a  number  of 
grinding  wheels  in  various  departments  for  rough 
grinding  of  castings  and  general  purpose  work.  As  the  stands 
upon  which  these  wheels  are  used  are  generally  of  different 
makes  and  sizes,  it  is  not  uncommon  for  the  diameters  of 
the  wheel  ends  of  the  spindles  to  vary  from  1/16  to  1/4 
inch  or 'more.  Thus,  while  1 6 -inch  wheels  might  be  used 
in  several  departments,  it  is  necessary  to  carry  a  super- 
fluous stock  to  accommodate  the  various  sized  spindles. 
To  overcome  this  difficulty,  many  manufacturers  make  a 
practice  of  re-bushing  their  grinding  wheels  as  occasion 
requires,  thereby  eliminating  the  necessity  of  carrying  in 
stock  individual  grinding  wheels  for  each  department  where 
the  sizes  of  the  wheel  spindles  vary.  The  wheels  are  or- 
dered with  the  proper  size  arbor  hole  to  fit  the  largest  spindle, 
and  with  facilities  easily  procured  they  can  be  readily  re- 
bushed  to  fit  the  other  sized  spindles  at  slight  expense. 

The  following  method  for  performing  the  work  in  question 
necessitates  but  a  slight  outlay  for  equipment  and  the  results 
will  be  found  to  be  satisfactory.  The  necessary  tools  are  a 
cast-iron  disc  or  plate  as  shown  in  Fig.  3  7  and  several  plugs 
of  the  same  diameter  as  the  various  arbors  on  which  the 
wheels  are  mounted.  The  plate  should  be  as  large  in  diam- 
eter as  the  largest  wheel  used,  and,  for  the  sake  of  illustra- 
tion, the  plate  shown  is  20  inches  in  diameter.  It  has  three 


ABRASIVES  AND    ABRASIVE   WHEELS 

feet  cast  on  it,  which  allows  level  setting  on  an  uneven 
surface,  should  occasion  require. 

The  rough  casting  is  mounted  in  a  large  lathe  chuck  and 
the  face  turned  off,  after  which  a  3/4-inch  hole  is  bored  and 
reamed  in  the  center.  The  next  step  is  to  turn  several 
grooves  1/4  inch  apart.  These  can  be  cut  with  an  ordinary 


Fig.  37. — Appliance  for  re-bushing  grinding  wheels. 

threading  tool,  and  are  used  to  set  the  grinding  wheel 
central  while  re-bushing  its  hole.  Two  heavy  lines  are  next 
scribed  on  the  disc  90°  apart,  and  near  these  lines  the 
circles  are  stamped  i,  2,  3,  4,  5,  6,  etc.  Several  plugs  are 
now  made  with  one  end  to  fit  the  hole  in  the  disc,  while  the 
diameters  of  the  large  ends  should  be  o.oo2-inch  larger 
than  the  arbors  on  the  grinding-wheel  stands.  This  slight 
clearance  is  sufficient  to  allow  the  wheels  to  slip  on  freely. 
The  large  portion  of  the  plugs  should  be  one  inch  longer 
than  the  thickness  of  the  grinding  wheels.  Thus,  if  wheels 

140 


RE-BUSHING  GRINDING  WHEELS 

with  a  2 -inch  face  are  used,  the  plugs  should  be  3  inches, 
as  shown  in  the  cut. 

In  re-bushing  a  grinding  wheel,  the  first  operation  is  to 
cut  out  the  original  lead  bushing  with  a  compass  saw. 
By  making  two  cuts  diametrically  opposite  one  another, 
the  bushing  is  easily  removed  by  means  of  a  few  light  taps 
with  a  hammer.  The  wheel  is  now  laid  on  the  disc  and 
carefully  arranged  in  the  center  by  means  of  the  nearest 
circle  to  its  periphery.  A  plug  of  the  correct  size  is  next 
inserted  and  the  new  bushing  cast  in  place.  Lead  is  the 
best  material  for  this  purpose,  although  any  scrap  stock 
of  low  melting  point  such  as  solder,  die-casting  metal,  etc., 
will  answer  the  purpose  equally  well. 

The  operation  of  re-bushing  wheels  is  so  simple  that  any 
boy  or  handy  man  can  do  the  work  in  a  satisfactory  manner, 
while  the  cost  of  the  necessary  outfit  should  not  exceed 
twenty  dollars. 


CHAPTER  TWELVE 

SUGGESTIONS  TO  FOLLOW  IN  ORDERING  GRINDING  WHEELS 

Information  to  be  given  with  grinding-wheel  order — Factor  governing  selec- 
tion of  wheels — How  to  determine  what  kind  of  a  wheel  should  be  used 
— Ordering  special  wheels. 

'"T'HE  majority  of  grinding-wheel  manufacturers  include 
*•  in  their  catalogues  a  list  of  various  grinding  operations, 
together  with  the  grits  and  grades  generally  recommended 
for  the  different  work.  The  object  of  these  lists  is  to  guide 
the  purchasing  agent  in  the  selection  of  grinding  wheels  for 
various  purposes. 

An  order  for  grinding  wheels  should,  of  course,  give  the 
diameter,  thickness,  size  of  arbor  hole  and  quantity  desired 
and,  in  case  of  a  repeat  order,  the  grit  and  grade.  Other- 
wise it  is  a  good  plan  to  refer  to  the  tables  previously  men- 
tioned or  give  with  the  order  full  and  complete  information 
describing  how,  and  for  what  purpose,  the  wheel  is  to  be 
used.  This  information  is  of  great  value  to  the  grinding- 
wheel  manufacturer  in  filling  the  order  intelligently,  and 
also  it  is  the  means  of  saving  much  valuable  time  as  un- 
necessary correspondence  for  the  purpose  of  gaining  full 
information  is  thereby  eliminated. 

There  are  indeed  many  factors  governing  the  proper  selec- 
tion of  grinding  wheels  as  the  following  data,  furnished  the 
writer  by  the  Abrasive  Company  of  Philadelphia,  plainly 
illustrate.  It  is  with  pleasure  that  the  writer  incorporates 
this  material  in  his  work  as  it  states  fully  just  how  the  grind1 
ing-wheel  manufacturer  views  an  order  for  grinding  wheels 
that  he  may  fill  the  same  correctly,  thereby  being  assured 
of  future  business. 

142 


SUGGESTIONS  IN  ORDERING  GRINDING  WHEELS 

"In  order  to  obtain  the  best  results,  it  is  necessary  to 
furnish  full  information  to  the  wheel  manufacturer. 

"It  is  true  that  the  size  is  generally  given,  but  it  is  also 
necessary  to  know  the  kind  of  material  to  be  ground,  how 
the  work  is  applied  to  the  wheel  and  whether  the  same  is 
edge  or  surface  contact.  In  describing  the  class  of  materials 
to  be  ground,  it  is  necessary  to  cover  the  point  fully,  or  best 
results  will  not  be  obtained,  no  matter  whose  make  of 
wheel  is  used. 

"  It  is  necessary  to  know  the  type  of  machine  on  which  the 
wheels  are  to  be  used,  whether  the  same  is  of  the  bench, 
floor,  swing  frame,  flexible  shaft  or  cylindrical  type. 

"  When  possible,  give  the  make  of  the  machine.  It  is  im- 
portant to  know  the  construction,  whether  light,  or  heavy 
and  rigid,  for  the  following  reasons:  A  heavy  machine 
will  absorb  vibration  and  for  this  reason  a  softer  grade 
of  wheel  may  be  used,  thereby  increasing  production, 
whereas  a  harder  grade  wheel  would  be  required  for  the 
same  work  on  a  light  machine,  due  solely  to  the  construc- 
tion of  the  machine.  If  the  machine  is  light  and  vibrates, 
production  is  sacrificed  on  account  of  the  necessity  of  fur- 
nishing a  harder  grade  wheel. 

"  Strong  rigid  machines,  set  on  firm  foundations,  allow  the 
grade  of  wheel  to  be  used  that  will  produce  the  best  results. 

"To  determine  the  proper  grit  and  grade,  it  is  necessary 
to  know  the  kind  of  material  to  be  ground.  With  this  in- 
formation, the  correct  abrasive  can  be  selected.  If  steel,  is 
it  hard  or  soft?  If  malleable  iron,  is  it  hard  or  annealed? 
If  iron,  is  it  cast,  wrought  or  chilled?  In  the  grinding  opera- 
tion, it  is  necessary  to  know  whether  there  is  line  or  surface 
contact.  To  describe  fully  what  we  mean,  the  following 
illustration  will  suffice:  If  the  operation  was  grinding 
balls,  there  would  be  line  contact,  and,  in  such  a  case, 
it  would  be  necessary  to  furnish  a  hard  grade  wheel.  If 
the  operation  was  internal  grinding,  there  would  be  a 
large  surface  contact,  thereby  requiring  a  softer  grade 
wheel,  and  in  most  cases  a  coarser  grit. 


ABRASIVES  AND  ABRASIVE  WHEELS 

"Whether  the  work  is  to  be  ground  wet  or  dry  largely 
determines  the  grade  of  wheel  to  be  furnished.  In  many 
cases,  a  harder  grade  of  wheel  can  be  used  if  the  grinding 
is  done  wet,  as  this  practice  prevents  the  work  from  over- 
heating. 

"Wheels  are,  under  ordinary  conditions,  recommended  to 
run  5,000  to  5,500  surface  feet  per  minute,  although  in 
many  kinds  of  grinding,  they  should  be  run  much  slower. 
If  a  wheel  is  too  hard  for  the  operation,  good  results  can 
often  be  obtained  by  reducing  the  speed,  and  if  too  soft, 
this  condition  may  be  rectified  by  increasing  the  speed. 
It  is  seen,  therefore,  that  wheels  at  slow  speeds  tend  to 
act  softer,  whereas  wheels  at  high  speeds  appear  to  act 
harder.  In  stating  the  speed,  the  number  of  revolutions 
per  minute  should  be  given.  Wheels  used  on  cylindrical 
grinders  are  operated  at  about  5,500  peripheral  feet  per 
minute,  while  for  automatic  knife  grinding,  they  are  run 
as  slow  as  2,500  feet  per  minute  surface  speed.  It  is  seen, 
therefore,  that  speed  plays  an  important  part  in  a  successful 
grinding  operation. 

"  If  the  operation  for  which  wheels  are  to  be  ordered  is 
cylindrical  grinding,  the  diameter  of  the  pieces  to  be  ground 
should  be  given,  also  the  R.  P.  M.  of  the  work.  This  en- 
ables the  grinding-wheel  manufacturer  to  determine  the  work 
speed.  It  is  also  necessary  to  know  the  quality  of  finish  de- 
sired, as  this  is  largely  determined  by  the  grit  of  the  wheel. 

"If  the  operation  is  surface  grinding,  the  speed  in  linear 
feet  should  be  given.  It  is  important  also  to  know  the  table 
traverse,  or  cross  feed,  which  is  the  speed  with  which  the 
wheel  is  fed  across  the  work. 

"  If  the  wheel  is  other  than  regular,  a  blue  print  or  sketch 
should  accompany  the  order.  Oftentimes  the  work  to  be 
done  is  of  a  special  nature,  thus  a  sketch  of  the  work  will 
also  materially  aid  in  the  proper  selection  of  the  wheel. 
The  user  who  is  careful  to  give  required  information  is 
generally  the  one  who  is  getting  the  best  results  from  his 
grinding  wheels." 

144 


CHAPTER   THIRTEEN 

DESIGN    OF    DUST-COLLECTING   SYSTEMS 

(Reprinted  from  American  Machinist.) 

State  law  requirements — Design  of  wheel  hood — General  design — Size  of 
exhaust  pipe  for  different  size  wheels — Elbows — Collars — Method  of 
erection — Clean-out — Fan — Dust-collector — Exhaust  systems. 

TN  the  majority  of  states  where  manufacturing  is  carried 
1  on  to  any  extent,  laws  have  been  passed  compelling  the 
manufacturer  to  equip  grinding  and  polishing  departments 
with  a  suitable  system  for  carrying  away  the  dust.  The 
different  state  laws  vary  greatly  as  to  what  constitutes  an 
effective  dust -collecting  system;  some  being  very  rigid,  while 
others  are  quite  liberal. 

This  legislation  is  good  for  several  reasons.  In  the  first 
place,  it  protects  the  workman's  health.  The  removal  of 
dust  from  any  manufacturing  plant  affords  better  fire  pro- 
tection. It  saves  quite  an  amount  of  material  in  cases 
where  brass,  copper,  nickel  or  other  comparatively  valu- 
able metals  are  ground  or  polished.  It  is  a  fact  that  in 
many  cases  where  dust-collecting  systems  have  been  in- 
stalled, enough  metal  has  been  saved  in  the  course  of  a  few 
years  to  offset  the  cost  of  the  installation. 

The  first  point  to  consider  in  any  dust-collecting  system 
is  the  design  of  the  hood  that  covers  the  wheel.  Fig. 
38  illustrates  an  effective  hood,,  made  by  the  B.  F. 
Sturtevant  Co.,  Hyde  Park,  Mass.  The  lower  part  of 
the  hood  forms  a  receptacle  for  containing  the  heavier 
part  of  the  material  removed  from  the  work,  and  is 


ABRASIVES  AND  ABRASIVE  WHEELS 

provided  with  a  swing  clean-out  gate.  It  is  important 
to  collect  as  much  metal  and  abrasive  as  possible  in  the 
hood,  as  this  saves  wear  on  the  piping,  fan  and  collector. 
By  referring  to  Fig.  39,  it  is  seen  that  the  hood  in  ques- 


Fig.  38. — Wheel  hood  designed  for  catching  dust. 

tion  is  hinged  on  one  side  to  facilitate  the  removal  of 
the  wheel  as  occasion  requires. 

The  size  of  the  branch  pipes  connected  to  the  hoods  is 
determined  by  the  size  of  the  wheels  used.  The  following 
table  gives  the  general  rules  recommended  by  the  Sturte- 
vant  Company.  These  are  general  and  open  to  modification 
in  cases  of  special  or  wide-faced  wheels. 

146 


DESIGN  OF   DUST-COLLECTING  SYSTEMS 


Pipe  Sizes  Wheel  Sizes 

2  inch 4  inch. 

3  inch 4  to    6 

3>2  inch 8  to  10 

4  inch , 1 2  to  16 

4K  inch 18 

5  inch 20 

6  inch 22  to  26 

The  elbcws  used  in  connecting  the  branch  pipes  with  the 
main  pipe  collars  are  generally  made  in  four  sections  for 
45°  elbows  as  shown  in  Fig.  40  A.  This  design  allows  a 


Fig-  39- — Wheel  hood  in  opened  position. 

comparatively  smooth  interior,  thus  reducing  friction  to  a 
minimum.  As  a  further  means  of  reducing  friction,  the 
radii  of  all  elbows  should  at  least  equal  the  diameter  of  the 
pipe,  and  should  exceed  this  when  it  is  practical  to  have 
them  do  so. 

The  collars  that  connect  the  branch  pipes  with  the  main 
U7 


ABRASIVES  AND  ABRASIVE  WHEELS 


pipe  should  intersect  at  an  angle  of  45°,  or  less,  when 
measured  from  the  center  line  of  the  main  pipe.  A  greater 
angle  than  this  creates  unnecessary  friction,  which  impairs 


Fig.  40. — Piping  details  for  dust-collecting  system:     "A,"  elbow  joint; 
"B,"  cap  cleanout;  "C,"  main  pipe  joint;  "D,"  main  pipe  cleanout. 

the  effectiveness  of  the  system,  and  throws  an  unnecessary 
load  on  the  fan. 

The  main  pipes  should  be  placed  on  the  floor  or  between 
the  ceiling  and  floor  when  possible.  By  referring  to  Fig.  41, 
which  is  a  plan  and  end  elevation  of  an  exhaust  system  in- 
stalled in  a  manufacturing  plant,  it  is  seen  that  the  area 
of  the  main  pipe  increases  for  every  two  branch  pipes 
added.  This  is  essential  in  maintaining  a  uniform  draft. 

Without  doubt,  the  ideal  main  pipe  would  be  one  having  a 
constant  taper  from  end  to  end.  Such  a  pipe,  however, 
would  not  be  practical  to  construct,  and,  furthermore, 
would  be  unnecessarily  expensive.  The  general  rule,  which 
by  the  way,  is  sometimes  open  to  change,  is  to  have  the 
main  pipe  sections  25  per  cent,  larger  than  the  sum  of  the 
openings  that  lead  to  it.  Thus,  in  Fig.  41,  the  section 
marked  A  should  be  25  per  cent,  larger  than  the  combined 
areas  of  the  two. branch  pipes  opening  into  it.  Section  B 
should  be  25  per  cent,  larger  than  the  combined  areas  of  its 

148 


DESIGN  OF   DUST-COLLECTING  SYSTEMS 

branch  pipes,  plus  the  area  of  section  A,  and  so  on.  From 
this,  it  is  seen  that  there  is  always  a  25  per  cent,  increase 
to  insure  cutting  down  the  air  resistance  to  a  minimum. 

The  joints  of  the  main  pipe  should  be  formed  as  shown 
in  Fig.  40  C  the  straight  line  always  being  at  the  lowest 


Fig.  41 . — Plan  and  end  elevation  of  a  dust-collecting  system. 

point.     This  is  important,  as  it  helps  to  keep  the  pipe  free 
from  obstructions. 

A  cleanout  should  be  placed  in  every  section  of  the 
main  pipe,  also  at  every  elbow.  This  should  be  as  air-tight 
as  possible.  Fig.  40  D  illustrates  the  type  of  cleanout 
used  for  this  purpose.  It  consists  simply  of  a  slide  conform- 

149 


ABRASIVES  AND  ABRASIVE  WHEELS 

ing  to  the  curve  of  the  pipe.  The  length  of  the  slide  should 
be  twice  its  width  to  avoid  cramping. 

A  cap  cleanout,  as  shown  in  Fig.  40  B  should  always  be 
located  at  the  end  of  the  main  pipe.  This  type  of  cleanout 
is  sometimes  seen  in  main  pipes.  This,  however,  is  poor 
practice  as  it  has  a  tendency  to  interrupt  the  free  passage 
and  force  of  the  draft,  thus  forming  a  pocket  where  ob- 
structions collect. 

In  exhaust  systems,  for  removing  dust  from  grinding  and 
polishing  wheels,  it  is  the  generally  accepted  practice  to 
place  the  fan  between  the  work  and  the  dust  collector.  In 
some  cases,  however,  the  collector  is  located  between  the 
work  and  the  fan.  Sometimes  two  collectors  are  used,  one 
on  the  intake  and  one  on  the  exhaust  side. 

Where  it  is  practicable  to  do  so,  the  fan  should  be  placed 
reasonably  near  the  work,  to  avoid  a  long  intake  pipe.  It 
should  also  be  near  the  ceiling  to  avoid  taking  up  valuable 
floor  space. 

The  size  and  speed  of  the  fan  determine  the  velocity  of 
the  draft,  which  should  be  sufficient  to  raise  a  column  of 
water  i>^  to  2  inches  in  a  U-shaped  tube  at  the  point  of 
weakest  suction,  which  is  farthest  away  from  the  fan.  The 
amount  of  suction  stipulated  in  some  of  the  recently  passed 
state  laws  is  in  excess  of  these  figures,  although  the  suction 
above  stated  is  sufficient  for  the  exhaust  system  in  question. 

Exhaust  systems,  as  applied  to  grinding  and  polishing 
wheels,  are  designed  to  carry  away  the  dust,  and  to  deposit 
it  at  a.  convenient  point.  The  collector  is  usually  placed 
out  of  doors,  but  it  should  be  within  a  reasonable  distance 
of  the  fan  to  avoid  a  long  exhaust  pipe. 


CHAPTER  FOURTEEN 

SAFEGUARDING   GRINDING   WHEELS 

(Reprinted  from  The  Iron  Age.) 

Why  wheels  break — Cause  of  accidents — How  wheels  are  packed  and  tested 
before  leaving  factory — Wheel  speeds — Mounting  wheels  properly — What 
causes  wheels  to  burst — Safety  flanges — Work  rest — Wheel  guards — 
Grinding  on  small  wheels — Precautions  for  the  workman. 

WHEN  we  stop  to  consider  that  grinding  wheels  are 
used  under  all  sorts  of  conditions,  both  good  and  bad, 
it  is  evident  that  serious  accidents  are  bound  to  happen  if 
precautions  for  proper  safeguarding  are  not  taken.  From 
the  writer's  practical  experience  with  grinding  wheels, 
covering  a  period  of  many  years,  and  from  observation  of 
the  conditions  under  which  grinding  wheels  are  used  in 
practically  every -branch  of  manufacturing,  it  is  his  opinion 
that  fully  95  per  cent,  of  the  accidents  due  to  the  breakage 
of  grinding  wheels  are  wholly  uncalled  for  and  could  be 
avoided  by  a  little  precaution  on  the  part  of  both  employer 
and  employee. 

The  following  is  a  list  of  the  principal  causes  of  grinding- 
wheel  failures  which  will  be  explained,  each  cause  being 
taken  up  separately  for  the  sake  of  convenience. 
Imperfect  wheels. 
Abnormal  wheel  speeds. 
'    Faulty  mounting  of  wheels. 
Lack  of  attention  to  work  rests. 
Loose-wheel  spindles. 

The  reliable  manufacturer  of  grinding  wheels,  whose 
products  are  to  be  found  in  every  city  and  town  in  the 
country,  spares  no  expense  to  make  sure  that  only  perfect 
wheels  are  placed  on  the  market.  This  has  been  explained 


ABRASIVES  AND  ABRASIVE  WHEELS 

under  the  head  of  grinding-wheel  manufacture,  and  no 
further  comment  is  necessary. 

Extreme  care  is  also  exercised  in  packing  wheels  for  ship- 
ment that  accidents  in  transit  may  be  avoided.  The  larger 
wheels  are  packed  in  individual  boxes  with  sawdust.  The 
smaller  wheels,  or  rather  comparatively  thin  wheels,  receive 
the  added  protection  of  corrugated  strawboard.  Before  a 
wheel  is  mounted  for  use,  it  should  be  lightly  tapped  with 
a  small  hammer.  If  it  emits  a  bell-like  sound,  it  is  safe. 
If  it  gives  out  a  dull  sound,  it  should  be  condemned  as  un- 
safe. Accidents  through  defective  wheels  are,  happily,  very 
rare. 

Reliable  makers  of  grinding  wheels  always  mark  on  the 
tags  of  regular  wheels  the  proper  operating  speed,  and  the 
consumer,  or  in  the  case  of  a  large  concern,  the  millwright 
and  the  mechanical  engineer,  should  pay  a  little  attention 
to  this  important  detail.  The  proper  operating  speed  for 
a  common  wheel  in  vitrified  or  silicate  bond  is  5,000  feet 
per  minute.  This  is  a  safe  speed  and  it  is  productive  of 
economical  results.  The  thin,  special  wheels  made  by  the 
vulcanite  and  shellac  processes,  can  be  run  much  faster 
with  perfect  safety,  owing  to  the  strong  nature  of  the  bond. 
As  a  matter  of  fact,  a  vulcanite  wheel  has  to  be  run  at  a 
high  peripheral  speed  to  show  efficiency. 

There  are  several  reasons  why  grinding  wheels  are  over- 
speeded.  Indifference  on  the  part  of  the  millwright  who 
installed  the  grinding  stand  is  sometimes  the  cause.  Not 
having  just  the  proper- sized  pulley  for  the  line  shaft,  he 
is  likely  to  substitute  a  different  size,  often  larger  than  is 
called  for,  which  of  course  overspeeds  the  wheel.  Many 
grinding-wheel  stands  are  equipped  with  a  two-  or  three- 
step  cone,  the  object  being  to  speed  up  the  wheel  as  it 
wears  down.  Neglecting  to  shift  the  belt  to  its  lowest 
speed  after  installing  a  new  wheel,  results  in  overspeeding. 
While  grinding-wheel  stands  of  the  above  type  are  no  doubt 
very  convenient  as  regards  speed  adjustments,  they  are, 
at  the  same  time,  a  source  of  constant  danger,  as  an  in- 


SAFEGUARDING  GRINDING  WHEELS 

different  or,  in  some  cases,  a  green  workman  is  liable  to 
shift  the  belt  to  suit  himself,  ignoring  limits  of  safety. 

A  safe  and,  at  the  same  time,  an  economical  way  to  use 
ordinary  wheels,  and  one  that  is  giving  entire  satisfaction 
in  some  of  our  largest  manufacturing  concerns,  is  to  always 
buy  wheels  of  a  given  size.  When  new,  these  wheels  are 
mounted  on  a  stand,  the  spindle  of  which  runs  at  the  proper 
speed  for  the  diameter  of  the  wheel.  As  soon  as  the  wheels 
are  worn  down,  say  2  inches,  they  are  placed  on  another 
stand  running  at  a  higher  speed  and  so  on  until  the  wheel 
is  worn  down  to  a  stub.  The  above,  of  course,  applies  only 
to  wheels  having  a  constant  grade  from  periphery  to  hub. 
Wheels  having  an  increasing  grade  from  the  outside  to  the 
hole,  as  explained  elsewhere,  do  not  require  speeding  up 
as  they  wear  away. 

In  mounting  a  grinding  wheel,  the  lead  bushing  should 
slip  readily  over  the  spindle.  If  the  bushing  is  a  little  small, 
as  it  sometimes  is,  the  defect  can  be  readily  remedied 
by  means  of  a  bearing  scraper  or  an  old  file.  The  operator 
who  neglects  this  simple  precaution  and  mounts  a  wheel 
by  forcing  it  on  the  spindle,  is  taking  a  chance  of  meeting 
with  a  serious  accident,  as  tight  wheel  bushings  are  the 
source  of  the  majority  of  accidents. 

The  reason  for  this  is  quite  apparent,  as  lead,  the  material 
with  which  grinding  wheels  are  bushed,  expands  readily 
from  heat.  When  the  wheel  spindle  runs  warm,  as  it  in- 
variably does  after  being  in  use  a  few  hours,  the  spindle 
expands  a  little  from  the  heat.  The  lead  bushing  readily 
absorbs  a  part  of  the  heat  which  expands  it  several  thou- 
sandths of  an  inch,  owing  to  the  fact  that  lead  has  a  high 
co-efficient  of  expansion.  The  expansion  of  the  lead  throws 
an  undue  stress  on  the  wheel,  which,  added  to  the  stress 
to  which  the  wheel  is  subjected  from  centrifugal  force, 
is  sufficient  to  cause  it  to  burst. 

Wheel  flanges  should  be  at  least  one-third  of  the  diameter 
of  the  wheel,  and  should  always  be  recessed  as  shown  in 
Fig.  42.  Plain  flanges,  as  shown  in  Fig.  43,  are  dangerous, 


ABRASIVES  AND  ABRASIVE  WHEELS 

as  they  do  not  always  grip  the  wheel  properly,  a  slight 
crowning  of  either  wheel  or  flange  being  sufficient  to  cause 
them  to  grip  the  wheel  near  the  arbor  only.  Fig.  44  illus- 
trates another  source  of  trouble  caused  by  wheel  flanges 


Fig.  42. — Proper  design  of  wheel  flanges. 

Fig.  43. — Incorrect  in  design  as  recesses  are  absent. 

Fig.  44. — Fruitful  cause  of  accidents — two  flanges  of  different  sizes  on  one 

wheel. 
Figs.  45  and  46. — Two  types  of  safety  flanges. 

belonging  to  different  grinding  stands  becoming  mixed. 
The  outer  flange  being  smaller  in  diameter  than  the  inner 
one,  brings  an  undue  side  strain  on  the  wheel. 

Two  types  of  safety  flanges  are  shown  in  Figs.  45  and  46. 
While  flanges  of  this  type  will  prevent  a  split  fragment  of  a 
wheel  from  flying,  their  use  is  not  at  all  common.  As  a 
matter  of  fact,  the  average  manufacturer  considers  them  a 
nuisance.  Generally  speaking,  safety  flanges  are  not  neces- 
sary with  wheels  made  by  a  reliable  maker,  properly  mounted 
and  run  at  the  speed  recommended. 

When  the  nature  of  the  grinding  will  permit,  it  is  a  good 
plan  to  use  wheels  without  a  work  rest.  On  compara- 
tively heavy  work,  however,  a  rest  is,  of  course,  necessary 
as  the  workman  has  to  utilize  his  strength  in  holding  the 
work  to  the  wheel.  Rests  are  also  necessary  on  tool- 


SAFEGUARDING  GRINDING  WHEELS 

grinding  wheels,  and  other  wheels  used  for  general  purposes. 
It  is  with  the  last  two  classes  of  wheels  that  accidents  occur 
by  getting  the  work  caught  between  the  wheel  and  the  rest. 
This  generally  results  in  a  broken  wheel  and  consequent 


Fig.  47. — Sharpening  a  counterbore  on  an  unguarded  wheel. 

injuries  to  any  one  who  happens  to  be  in  the  path  of  the 
flying  fragments.  The  only  way  to  avoid  accidents  is  to 
keep  the  wheel  true  and  the  rest  adjusted  closely — within 
1/32  inch  of  the  face  of  the  wheel.  In  justice  to  the  manu- 
facturer, it  should  be  stated  that  accidents  of  this  kind 
are  in  nearly  every  case  caused  by  carelessness  on  the  part 


ABRASIVES  AND  ABRASIVE  WHEELS 

of  the  operator.  His  common  sense  and  mechanical  instinct 
should  tell  him  that  he  is  taking  desperate  chances  in 
allowing  a  wide  gap  between  the  wheel  and  the  work  rest. 

Loose  wheel  spindles  often  cause  wheels  to  break  as  they 
allow  the  wheel  to  run  out  of  balance  and  also  make  it 


Fig.  48. — Sharpening  the  peripheral  teeth  of  a  milling  cutter  on  an 
unguarded  wheel. 

impossible  to  keep  the  rest  adjusted  close  to  the  wheel. 
Babbitt  metal,  even  of  the  highest  quality,  is  cheap  as  com- 
pared to  the  consequences  of  injuries,  and  this  is  one  reason 
why  the  spindles  of  grinding-wheel  stands  should  be  re- 
babbitted  as  soon  as  they  show  noticeable  signs  of  wear. 

Many  states  have  passed  laws  requiring  manufacturers 
to  equip  the  grinding  wheels  used  in  their  plants  with  guards, 
the  object  being  to  keep  the  pieces  of  the  wheel  from  flying 

156 


SAFEGUARDING  GRINDING  WHEELS 

in  case  of  accident ;  not  to  keep  sparks  out  of  the  operator's 
eyes  as  one  might  judge  from  the  flimsy  guards  sometimes 
seen  over  grinding  wheels!  While  wheel  guards  are  not 
necessary  where  reliable  wheels,  properly  mounted,  are  in 


Fig.  49. — Sharpening  the  side  teeth  of  a  milling  cutter  on  an  unguarded 
wheel. 


operation,  their  use  is  to  be  strongly  recommended  as  they 
are  the  direct  cause  of  preventing  many  fatalities  from  ac- 
cidents caused  by  carelessness  on  the  part  of  the  operator. 
It  is,  however,  not  practicable  to  use  guards  over  the 
smaller  wheels  used  for  cutter  sharpening,  and  other  work  of 
like  nature.  Figs.  47,  48  and  49  illustrate  cutter-sharpening 


ABRASIVES  AND  ABRASIVE  WHEELS 

operations,  and  to  place  guards  over  these  wheels  would 
be  an  impossibility,  as  the  size  of  the  wheels  and  their  rela- 
tive position  to  the  work  are  different  with  every  operation. 
Accidents  with  wheels  of  this  kind  are  so  rare  as  to  cause 
no  comment.  There  are  two  reasons  for  this:  First  these 


Fig.  50. — Correctly  guarded  surface  grinding  wheel. 

small  wheels  are  comparatively  strong  for  their  size,  seldom 
breaking  unless  injured  by  being  dropped;  and  again  there 
is  no  reason  for  standing  directly  in  their  path. 

The  photographs  referred  to  were  taken  by  the  writer 
for  advertising  purposes.     In  each  case  the  operator  was 

158 


SAFEGUARDING  GRINDING  WHEELS 

asked  to  assume  a  working  position,  nothing  being  said 
about  standing  out  of  the  path  of  the  wheel.  However,  the 
operator  is  out  of  the  path  of  the  wheel  in  each  case,  and 
as  he  assumed  this  position  naturally,  one  would  infer  that 
a  skilled  mechanic  prefers  to  keep  out  of  the  path  of  cutter 
grinding  wheels.  As  a  matter  of  fact  he  does — not  because 


Fig.  51. — Guarded  wheel  on  a  Brown  &  Sharpe  surface  grinder. 

he  is  afraid  of  the  wheel  breaking  but  because  he  has  learned 
from  experience  that  to  stand  directly  in  the  path  of  an 
unguarded  wheel  nearly  always  results  in  particles  of  the 
abrasive  getting  in  the  eyes;  which  in  some  cases  requires 
the  services  of  a  skilled  surgeon  to  remove. 

Figs.  50  and  51  illustrate  two  types  of  surface  grinding 
wheels,  each  of  which  is  protected  by  a  suitable  guard. 
Guards  over  wheels  used  for  surface  grinding'  are  generally 
considered  necessary,  the  reason  for  this  being  that  surface 
grinding  wheels  frequently  break  as  they  are  of  a  soft,  open 
bond.  With  guards  of  the  types  shown  in  the  illustrations, 


ABRASIVES  AND  ABRASIVE  WHEELS 


Fig.  52. — Sheet-metal  wheel  and  spindle  guard. 


Fig.  53.— Wheel  and  belt  both  guarded. 
.160 


SAFEGUARDING  GRINDING  WHEELS 

serious  accidents  are  an  impossibility.  With  the  modern 
cylindrical  grinding  machine,  accidents  from  wheel  breakage 
are  almost  impossible  as  the  wheel  is  always  protected  by 
a  heavy  guard.  While  the  operator  generally  stands  di- 
rectly in  front  of  the  wheel  he  runs  no  chance  of  being  in- 


Fig.  54. — Sheet-metal  wheel  guard  arranged  for  adjustment. 

jured,  as  it  would  be  practically  impossible  for  a  piece  of  the 
wheel  to  strike  him.  Machines  of  this  kind  are  never 
used  without  wheel  guards.  In  fact,  a  guard  on  a  cylin- 
drical grinding  machine  is  a  necessity  in  keeping  water  from 
flying  all  over  the  shop,  as  this  class  of  grinding  is  invariably 
done  wet. 

Figs.  52  and  53  are  from  photographs  taken  in  the  shops 
of  two  well-known  railroad  companies.  By  referring  to 
Fig.  52,  it  is  seen  that  the  guard,  which  is  made  of  sheet  metal 
of  sufficient  thickness  to  withstand  the  shock  of  the  wheel 
fragments  in  case  of  accident,  is  also  provided  with  a  hood 
to  cover  the  projecting  threaded  end  of  the  spindle.  The 
object  of  this  hood  is  to  prevent  the  workman's  clothing 

161 


ABRASIVES  AND  ABRASIVE  WHEELS 

from  being  caught.  While  the  workman  in  this  illustration 
is  grinding  a  comparatively  small  piece  of  work,  he  is  taking 
no  chances  as  the  work  rest  is  placed  close  to  the  wheel. 

The  tool  grinder  shown  in  Fig.  53  is  of  a  type  often  seen 
in  railroad  shops.  It  is  provided  with  a  heavy  hood;  the 
work  rest  is  properly  adjusted,  and  a  guard  is  provided  to 
prevent  the  workman's  clothing  from  being  caught  in  the 


Fig-  55- — Novel  form  of  sheet-metal  wheel  guard. 

driving  pulley.  The  reason  that  railroad-shop  employees 
are  so  adequately  guarded  against  accidents  lies  in  the  fact 
that  the  shop  foreman  and  master  mechanics  in  charge 
are  fair-minded,  conscientious  men  who  have  gradually 
worked  up  from  unimportant  positions  to  positions  of  trust 
and  who,  therefore,  consider  the  workman's  welfare  from 
their  own  actual  shop  experience. 

Fig.  54  illustrates  another  tool-grinding  wheel  that  is 
properly  guarded.  The  hood,  which  is  made  of  i /4-inch 
sheet  metal,  is.  securely  bolted  to  the  frame  of  the  machine 
and  is  provided  with  an  adjustment  which  allows  it  to  be 
moved  towards  the  wheel  as  the  wheel  is  reduced  in  diam- 
eter. This  is  of  importance  as  a  guard  should  be  placed 

162 


SAFEGUARDING  GRINDING  WHEELS 

reasonably  close  to  prevent  the  wheel  fragments  from  fly- 
ing in  case  of  breakage.  The  work  rest  in  this  instance  is 
placed  close  to  the  wheel.  Although  the  machinist  in  this 
illustration  is  standing  in  front  of  the  wheel,  he  is  taking 


Fig.  56. — These  guards  are  inadequate  and  invite"  disaster. 

no  chance  as  it  would  be  impossible  for  a  section  of  a  wheel 
guarded  in  this  manner  to  get  away  from  the  hood.  The 
guard  over  the  driving  pulley  deserves  mention.  It  is 
made  of  i-i /2-inch  iron  pipe  and  covered  with  heavy  wire 
netting. 

Two  sheet-metal  guards  are  shown  in  Fig.  55.    They  are 
easily  removed  when  it  is  necessary  to  change  wheels,  as 

163 


ABRASIVES  AND  ABRASIVE  WHEELS 

the  guard  in  the  foreground  shows.  The  working  position 
of  the  guards  is  shown  by  the  guard  in  the  background. 
These  guards  are  adjustable  and  can  be  moved  toward  the 
face  of  the  wheels.  They  are  novel  in  construction,  the 
body  being  cut  from  one  piece  of  heavy  sheet  metal. 

Figs.  56  and  57  illustrate  a  wholly  inadequate  type  of 
grinding- wheel  guards  that  are,  unfortunately,  in  common 


-  57- — This  guard  is  too  flimsy  to  stop  flying- wheel  fragments  in  case  of 
an  accident. 


use.  While  guards  of  this  kind  are  often  passed  by  factory 
inspectors  who  are  lacking  in  practical  knowledge,  they  are 
worse  than  no  guards  at  all,  as  a  section  of  a  burst  wheel 
would  crumple  them  up  like  so  much  cardboard. 

In  cases  where  grinding  wheels  burst,  resulting  in  fatali- 
ties, it  is  sometimes  a  difficult  matter  to  determine  who  is 
at  fault,  the  employer  or  the  employee.  Is  it  justice  to 

164 


SAFEGUARDING  GRINDING  WHEELS 

compel  a  manufacturer  to  pay  heavy  damages  for  fatalities 
brought  about  (as  they  often  are)  by  wanton  carelessness 
on  the  part  of  the  operator?  If  the  employer  neglects  to 
have  adequate  guards  placed  over  grinding  wheels,  where 
there  is  a  law  requiring  him  to  do  so,  it  would  seem  that  he 
was  criminally  negligent  in  cases  where  fatalities  result 
from  the  bursting  of  grinding  wheels.  However,  let  it  be 
assumed  that  the  wheel  is  properly  guarded  and  that  the 
operator  himself  removes  the  guard  for  some  reason  and 
by  so  doing  is  injured.  Should  the  employer  be  compelled 
to  pay  damages  in  this  case?  Assuming  that  one  operator 
removes  a  wheel  guard  and  neglects  to  replace  it,  another 
operator  being  injured  on  the  same  wheel  a  short  time  after- 
ward, who  is  to  blame  in  this  case,  the  operator  who  re- 
moved the  guard,  the  operator  who  afterward  used  the 
wheel  without  the  guard  or  the  employer  who  was  ignorant 
of  the  whole  proceeding?  These  are,  of  course,  questions 
for  the  courts  to  decide,  and  decisions  in  cases  of  this  kind 
are  not  easily  reached  by  any  means. 

In  questions  where  the  safety  of  employees  is  concerned, 
labor  and  capital  should  co-operate.  The  working-man 
should  bear  in  mind  the  fact  that  it  is  an  impossibility  for 
him  to  earn  a  living  without  assuming  some  risk,  and  where 
the  employer  provides  all  possible  safeguards  against  acci- 
dents, the  employee  should  see  to  it  that  these  safeguards 
are  not  removed  or  destroyed. 


CHAPTER  FIFTEEN 

ABRASIVE    PAPERS  AND   CLOTHS* 

Abrasive  substances  used  in  making  abrasive  paper — History  of  abrasive  paper 
— How  abrasive  paper  and  cloth  is  manufactured — Grades  of  abrasive 
paper  and  cloth — Finding  percentage  of  iron  in  garnet — Testing  garnet 
paper — Paper  and  cloth  abrasive  discs — Testing  discs  for  efficiency. 

ABRASIVE  papers  and  cloths,  the  abrasive  coating  of 
**  which  is  emery,  Carborundum,  garnet,  flint,  Aloxite, 
etc.,  are  to  be  found  in  practically  every  branch  of  manu- 
facturing from  the  small  country  planing  mill  or  machine 
shop  to  the  immense  furniture  factory  or  automobile  plant. 
Large  quantities  are  also  consumed  by  tanneries  and  other 
leather  workers.  Comparatively  little  seems  to  be  known 
concerning  the  manufacture  of  these  staple  articles,  save 
from  the  meager  accounts  given  now  and  then  by  salesmen. 

All  abrasive  papers  and  cloths  are  made  in  the  same  man- 
ner, with  the  exception  of  abrasive  discs,  which  will  be 
considered  later.  We  can  explain  the  process  followed  by 
taking  up  the  subject  of  garnet  paper. 

While  the  use  of  abrasive  materials  dates  from  remote 
times,  the  use  of  coated  paper  and  cloth  is  a  comparatively 
modern  innovation.  Some  two  hundred  years  ago  it  was 
common  practice  for  New  England  cabinet  makers  who 
lived  near  the  seacoast  to  use  the  dried  skins  of  dogfish 
and  sharks  for  smoothing  wood.  Any  one  who  has  had 
occasion  to  deal  with  the  above-named  fish  in  the  live  state 
will  admit  that  their  skins  are  excellent  abrasives  in  a  literal 

*  The  above  chapter  is  a  consolidation  of  two  articles:  "Abrasive  Paper 
and  Cloth,"  originally  published  in  The  Iron  Tradesman,  and  "The  Selection 
of  Garnet  Paper,"  which  first  appeared  in  The  Wood  Worker,  to  which  the 
writer  has  added  some  further  material  concerning  the  testing  of  abrasive 
discs. 

166 


ABRASIVE  PAPERS  AND  CLOTHS 

sense,  as  a  single  indiscreet  rubbing  contact,  on  the  naked 
arm,  for  instance,  invariably  draws  blood  in  a  dozen  places. 
However,  as  our  forefathers  could  not  always  take  the  time 
to  go  shark  fishing  when  the  stock  of  this  "natural  abrasive" 
ran  low,  necessity  prompted  them  to  invent  a  substitute 
which  resulted  in  the  abrasive  paper  and  cloth  of  the  present 
day. 

As  near  as  we  can  ascertain,  emery  cloth  and  sand-paper 
were  invented  about  two  hundred  and  fifty  years  ago,  the 
process  of  manufacture  being  very  primitive,  consisting  of 
coating  the  backing  with  glue,,  liberally  covering  it  with  the 
desired  abrasive,  shaking  off  the  superfluous  material  and 
hanging  the  sheets  up  to  dry. 

Wonderful  improvements  have  been  made  in  the  manu- 
facture of  abrasive  papers  and  cloths,  the  slow  hand  methods 
of  a  few  generations  ago  being  superseded  by  the  modern 
coating  machine,  which  turns  out  material  by  the  mile.  The 
process  is  practically  the  same  for  both  paper  and  cloth 
backing  and  can  be  described  as  follows :  The  web  of  paper, 
traveling  at  high  speed,  passes  under  a  printing  attachment 
which  imprints  the  brand,  number,  etc.,  at  regular  intervals. 
Next  it  passes  through  a  series  of  rollers  wherein  the  top 
side  is  given  a  coat  of  glue,  which  is  distributed  in  much  the 
same  manner  that  ink  is  applied  to  the  type  in  a  large  print- 
ing press.  The  glue-coated  paper  now  passes  under  a 
large  hopper  from  an  opening  in  the  base  of  which  the  grain 
flows  in  a  steady  stream,  just  a  little  wider  than  the  width 
of  the  paper  being  run.  The  amount  of  running  grain  is 
regulated  to  allow  slightly  more  to  flow  than  will  stick  to 
the  paper,  the  superfluous  material  being  carried  away  by 
mechanical  means,  the  exact  nature  of  which  most  manu- 
facturers wish  to  keep  to  themselves.  By  means  of  two 
endless  chain  belts,  carrying  cross  sticks  at  regular  intervals, 
the  paper  is  caught  up  in  long  loops  and  carried  to  another 
coating  machine  where  the  sizing,  or  upper  coating  of  glue, 
is  applied.  This  covers  the  upper  surface  of  the  grain,  and 
as  it  unites  with  the  lower  coat  to  a  certain  extent  each 

167 


ABRASIVES  AND   ABRASIVE  WHEELS 

grain  is  firmly  embedded  in  a  matrix.  The  paper  is  now- 
caught  up  on  more  sticks,  where  it  travels  up  and  down  the 
long  drying  room,  the  process  of  drying  being  hastened  by 
carefully  regulated  blasts  of  warm  air.  The  paper  finally 
reaches  the  winding  machine,  where  it  is  wound  in  rolls  of 
about  four  feet  in  diameter.  From  there,  it  goes  to  the 
storage  room,  where  it  is  thoroughly  aged  before  being  sent 
to  the  cutting  room.  It  is  of  the  utmost  importance  to 
age  the  paper  before  putting  it  on  the  market,  as  green 
paper,  as  it  is  termed  by  the  manufacturer,  is  very  short 
lived,  owing  to  the  fact  that  the  glue  is  not  set  sufficiently 
to  hold  the  grain  firmly  in  place. 

From  the  store  room,  the  rolls  go  to  the  cutting  room, 
where  they  are  prepared  in  marketable  sizes,  consisting  of 
9x11  sheets,  in  quires  and  reams,  and  5o-yard  rolls  of 
various  widths.  Emery  cloth  is  sold  in  9x11  sheets  and  in 
rolls  9,  1 8  and  27  inches  wide.  The  grits  run  from  crocus 
to  3-1/2.  Emery  paper  is  sometimes  sold  in  rolls,  but 
there  is  more  demand  for  this  material  in  sheet  form. 
Carborundum  paper  can  be  bought  in  both  rolls  and  reams 
in  all  grits  from  20  to  F  F.  As  this  material  is  used  ex- 
tensively in  the  boot  and  shoe  industry  for  heel  scouring, 
heel  breasting  and  fore-part  buffing,  it  is  also  cut  in  odd  sizes 
and  shapes  to  fit  various  machines  used  for  the  above  pur- 
poses. Carborundum  cloth  can  be  had  in  all  grits  from 
4-1/2  to  F  F  in  9,  18  and  24  inch  rolls  or  9x11  sheets. 

There  are  four  kinds  of  garnet  paper,  known  to  the  trade 
as  follows:  Finishing  paper,  used  for  rubbing  varnish, 
which  is  made  in  all  grits  from  i  to  6/0;  double-faced 
finishing  paper,  in  the  same  grits,  which  is  coated  on  both 
sides  and  stripped  apart  as  needed,  the  grits  being  the  same 
as  for  ordinary  finishing  paper;  cabinet  paper  (ordinary 
sheet  garnet  paper)  in  numbers  from  3-1/2  to  6/0,  and  roll 
paper  in  numbers  3-1/2  to  4/0.  Roll  paper  is  furnished  in 
standard  widths  of  18,  24,  30,  36,  40,  42  and  48  inches. 
Garnet  cloth  is  always  run  in  rolls  of  28  inches  wide,  but 
can  be  had  in  any  desired  width.  The  bulk  of  garnet  paper 

1 68 


ABRASIVE  PAPERS  AND  CLOTHS 

is  used  in  the  wood-working  industries,  but  it  also  furnishes 
an  excellent  material  for  finishing  comparatively  soft 
metals  such  as  aluminum,  copper,  very  soft  brass,  etc. 
Ordinary  sand-paper  is  made  in  the  same  sizes  and  numbers 
as  garnet  paper  and  is  used  principally  for  smoothing  com- 
paratively soft  woods.  In  ream  form,  it  is  sold  in  every 
hardware  and  general  store  throughout  the  civilized  world 
to  customers  who  desire  a  few  sheets  at  a  time. 

Abrasive  paper  and  cloth  are  also  made  in  disc  form  for 
finishing  metals  on  the  disc  type  of  grinder.  As  the  back- 
ing of  this  material  is  very  heavy,  and  the  coating  extra 
thick,  it  is  not  practicable  to  run  it  off  in  mile  lengths,  thus 
it  is  coated  in  long  strips  of  approximately  200  feet.  After 
drying,  the  discs  are  cut  from  the  strips  by  means  of  heavy 
dies  in  a  hydraulic  press.  Some  makers  have  processes  for 
coating  discs  after  they  are  cut  to  shape,  the  Besley  discs 
with  the  spiral  groove  being  a  good  example  of  this  practice. 
The  majority  of  these  special  methods  are  covered  by  patent. 

Contrary  to  the  general  impression,  there  is  very  little 
profit  in  the  manufacture  of  abrasive  paper  and  cloth.  This 
statement  is  not  made  at  random,  simply  for  the  sake  of 
filling  up  space,  but  from  actual  observation  of  the  manu- 
facture of  the  products  in  question.  Therefore  the  writer's 
advice  to  the  consumer  who  aims  to  use  efficient  material  is 
to  purchase  standard  priced  goods.  Owing  to  the  fact  that  the 
margin  of  profit  is  small,  the  maker  cannot  cut  prices  to  any 
extent  and  supply  high-quality  material  at  the  same  time. 

The  superintendent  and  the  purchasing  agent  of  any 
concern  where  garnet  paper  is  used  to  any  extent,  are  fre- 
quently interviewed  by  garnet-paper  salesmen.  As  the 
salesman's  duty  is  to  sell  goods,  each  and  every  one,  of 
course,  has  just  the  material  that  will  surely  reduce  produc- 
tion costs.  Thus  the  question  arises:  "Whose  paper  is  the 
most  efficient  ?"  It  is  impossible  to  answer  this  question  off- 
hand, but  there  are  a  few  simple  tests  that  any  manufacturer 
can  make  in  his  spare  time,  and  the  data  thus  obtained  is 
reliable. 

169 


ABRASIVES  AND  ABRASIVE  WHEELS 

Any  one  who  is  conversant  with  the  working  of  a  three- 
drum  sander  realizes  that  a  machine  of  this  type  calls  for  a 
paper  with  a  very  strong  backing;  otherwise  the  paper  is 
liable  to  tear  before  the  grain  is  worn  to  a  point  of  useless- 


Fig.  58. — Simple  device  for  testing  the  strength  of  abrasive  papers. 

ness.  To  test  the  strength  of  the  backing  we  can  proceed 
as  follows:  First  a  frame  as  shown  at  (A)  Fig.  58  is  sus- 
pended from  a  convenient  overhead  timber.  The  cross 

170 


ABRASIVE  PAPERS  AND  CLOTHS 

piece  should  be  about  five  feet  from  the  floor.  A  common 
wood  clamp  (B)  is  fastened  to  the  cross  piece  by  means 
of  another  clamp  (C).  The  tray  (D)  is  suspended  from  the 
clamp  (E)  by  means  of  short  ropes  (G)  and  two  wire  hooks  (F) . 
(H)  is  the  sample  of  paper  to  be  tested.  This  is  cut  length- 
wise from  a  roll  of  paper  and  should  be  about  9  inches  long 
and  exactly  i  inch  wide.  The  ends  of  the  paper  should 
extend  about  2  inches  in  the  jaws  of  the  clamps,  which  must 
be  fastened  securely. 

The  next  step  is  to  place  weights,  one  at  a  time,  on  the 
tray  until  the  paper  breaks;  pieces  of  babbitt  metal  are 
excellent  for  this  purpose.  By  weighing  the  amount  of 
metal  necessary  to  break  the  paper,  we  readily  ascertain  the 
breaking  strain  per  linear  inch.  It  is  evident  that  the 
paper  which  supports  the  greater  weight  is  the  strongest. 
The  results  of  these  tests  should  be  entered  in  a  note-book, 
giving  the  make  of  paper,  mn  number,  grit  number,  and 
date  of  the  test.  It  is  a  well-known  fact  that  all  garnet- 
paper  salesmen  lay  great  stress  on  the  strength  of  their 
papers,  but  the  practical  man  who  takes  the  time  to  make 
the  simple  test  here  described,  between  several  makes  of 
papers,  can  readily  determine  for  a  certainty  which  is  the 
strongest.  Furthermore,  the  simple  appliance  used  (which 
costs  practically  nothing)  is  as  efficient  for  all  practical 
purposes  as  the  expensive  paper-testing  machines  used  by 
the  paper  manufacturers. 

Oxide  of  iron,  an  impurity  which  is  often  present  in  garnet v 
is  a  detriment  to  fast  cutting,  and  it  generally  indicates  that 
the  grain  was  not  properly  cleaned.  To  determine  the 
amount  of  this  impurity,  a  square  foot  of  unused  paper  should 
be  boiled  for  an  hour  or  so  in  a  clean  receptacle;  this  will 
detach  the  grain  from  the  backing.  The  grain  thus  ob- 
tained is  carefully  washed  and  dried,  then  spread  out  on  a. 
piece  of  paper  and  carefully  gone  over  with  an  ordinary 
horseshoe  magnet,  which  readily  attracts  the  grains  contain- 
ing any  amount  of  oxide  of  iron.  These  are  placed  in  a  little 
pile,  and  when  the  operation  is  complete,  we  have  two. 


ABRASIVES  AND  ABRASIVE  WHEELS 

samples  of  grain— one  containing  iron  and  another  free  from 
this  impurity. 

To  obtain  the  percentage  of  iron,  we  must  measure  each 
pile  by  volume.  This  can  be  done  with  any  small  re- 
ceptacle; an  empty  38-caliber  cartridge  shell  will  answer 
the  purpose  very  well.  Suppose  we  find  ninety  shellfuls 
of  grain  that  was  unattracted  by  the  magnet  and  ten  that  the 
magnet  picked  up.  In  this  case,  it  is  evident  that  the  grain 
contains  10  per  cent,  of  iron.  If  subsequent  tests  of  grain 
taken  from  another  make  of  paper  yield  15  per  cent,  of  iron, 
it  is  apparent  that  the  first  sample  was  of  better  quality. 
The  results  of  these  tests  should  also  be  entered  in  the  note- 
book for  future  reference. 

To  test  the  working  efficiency  of  any  make  of  paper  is  also 
a  comparatively  simple  operation.  Here  we  can  use  what 
the  salesman  terms  a  "fifty  fifty"  test.  Let  it  be  assumed 
that  we  are  using  belts  18  feet  long.  We  can  make  up  a 
belt  composed  of  9  feet  of  one  make  of  paper  and  9  feet 
of  another  make.  It  is  obvious  that  the  paper  that  gives 
out  first  is  of  the  poorer  quality.  A  test  of  this  kind  causes 
the  salesman  who  supplied  the  paper  of  poorer  quality  to 
scratch  his  head  in  perplexity.  On  these  occasions  it  is 
up  to  the  salesman  to  frame  a  good  excuse  or  retire  from  the 
field  as  gracefully  as  possible.  We  can  use  the  same  kind 
of  a  test  on  the  drum  sander,  provided  it  is  of  the  type  that 
takes  straight  paper — that  is,  not  wound  on  the  drums 
spirally.  By  covering  half  of  each  drum  with  one  make  of 
paper  and  the  other  half  with  another  make,  we  can  soon 
arrive  at  a  definite  conclusion. 

The  tests  here  described,  which  are  not  known  to  every 
user  of  garnet  paper,  were  brought  to  the  writer's  notice 
while  traveling  as  a  salesman  for  one  of  the  leading  garnet- 
paper  manufacturers  and  the  data  obtained  from  them 
can  be  relied  upon.  Any  garnet-paper  salesman  can  cite 
numerous  instances  where  his  goods  have  won  out  over 
those  of  his  competitors,  but  he  always  keeps  quiet  con- 
cerning the  instances  wherein  he  has  failed.  This  is  one 

172 


ABRASIVE  PAPERS  AND  CLOTHS 

reason  why  it  is  a  good  plan  for  the  consumer  to  work  out 
his  own  tests  in  his  own  plant,  ever  bearing  in  mind  the 
fact  that  crucial  tests  should  result  in  cold,  hard  figures 
that  have  been  obtained  through  actual  common-sense  tests. 

The  practice  of  disc  grinding  has  become  quite  common 
during  the  last  fifteen  years  and  has  led  disc  manufacturers 
to  supply  their  products  in  many  different  abrasives  and 
combinations  of  abrasives  for  various  purposes.  Flint, 
quartz,  garnet,  emery,  corundum,  Carborundum,  Crystolon, 
Aloxite,  Alundum  and  Adamite  are  the  principal  abrasives 
employed  for  disc  grinding. 

Notwithstanding  this  formidable  array,  the  selection  of 
suitable  discs  is  a  simple  operation  compared  with  the  selec- 


Fig.  59. — Gas-burner  parts  finished  by  disc  grinding. 

tion  of  grinding  wheels.  Grinding  wheels  are  made  in  many 
different  degrees  of  hardness  to  suit  various  classes  of  work. 
With  grinding  discs,  however,  the  factor  of  grade  as  applied 
to  grinding  wheels  is  wholly  eliminated.  All  that  is  neces- 
sary, is  to  select  an  abrasive  that  proves  satisfactory,  the 
character  of  the  finish  desired  determining  the  grain  of  the 
disc. 


ABRASIVES  AND  ABRASIVE  WHEELS 

To  illustrate  the  principle  used  in  testing  discs  for  ef- 
ficiency, we  can  consider  the  pieces  shown  in  Fig.  59,  which 
are  gas-burner  parts,  made  of  cast  iron,  measuring  5  inches 
in  diameter.  The  finished  surfaces  measure  3/8  inch  across 
and  the  grinding  is  done  from  the  rough,  the  object  being 
to  make  a  good  joint  in  the  shortest  possible  time.  The 
grinding  operation  is  shown  in  Fig.  60. 

Here  it  is  seen  that  the  pieces  to  be  ground  are  held  by  a 
retaining '  device  and  also  that  they  are  weighted.  The 


Fig.  60. — Grinding  gas-burner  parts  on  a  horizontal  disc-grinder. 

object  of  the  weights  is  to  insure  a  good  contact.  The 
final  finishing  is  sometimes  done  by  hand  as  shown. 

To  determine  the  grinding  cost  with  a  given  make  of  disc, 
it  is  only  necessary  to  note  the  cost  of  the  disc,  its  life  and 
the  number  of  pieces  ground.  From  this  data  the  grinding 
cost  per  hundred  pieces  is  easily  computed. 

To  obtain  the  best  results,  the  abrasive  must,  of  course, 
be  suited  to  the  work,  and  while  it  is  a  well-known  fact  that 
flint  and  quartz  are  suitable  for  soft  wood,  garnet  for  hard 
wood,  emery  for  rough-steel  grinding  where  a  durable  disc 
is  required,  corundum,  Aloxite  and  Alundum  for  steel,  and 

i74 


ABRASIVE  PAPERS  AND  CLOTHS 

Carborundum  and  Crystolon  for  cast  iron,  the  actual  selec- 
tion is  often  controlled  by  the  makers  as  the  majority  of 
them  designate  their  discs  by  numbers,  preferring  to  keep 
the  actual  character  of  the  abrasives  to  themselves.  The 
object  of  this  practice  is  to  enable  the  disc  manufacturer 
to  be  reasonably  sure  of  securing  repeat  orders,  relying  on 
the  consuming  trade  to  order  by  number.  This  method  is 
not  without  advantage  to  the  consumer,  as  it  enables  him 
to  order  the  material  desired  without  having  to  resort  to  a 
list  of  abrasives,  which,  at  best,  are  confusing  to  those  not 
engaged  directly  in  the  abrasive  lines. 

Modern  disc  grinding  is  a  comparatively  new  branch  of 
engineering  practice,  and  when  we  stop  to  consider  that  it 
originated  from  a  sheet  of  sand-paper  glued  to  a  wooden 
disc  for  the  convenience  of  the  wood-worker,  the  present- 
day  possibilities  of  this  class  of  grinding  reflect  no  small 
degree  of  credit  on  the  experimenters  who  made  this  practice 
a  commercial  possibility. 


CHAPTER   SIXTEEN 

SURFACE   GRINDING 

Finishing  work  by  surface  grinding — Development  of  the  surface  grinding 
machine — Finishing  locomotive  guide  bars — Rotary  grinding  fixture — 
Wheel  speeds — Cuts — Die  grinding — How  dies  are  held — Grinding 
punches — Care  of  wheels — Magnetic  chucks — Demagnetizes— Proper 
wheel  selection  for  surface  grinding — Types  of  surface-grinding  machines 
— Standard  wheel  list. 

MANY  years  ago,  after  the  grinding  wheel  became  a 
commercial  possibility,  one  of  the  first  uses  to  which 
it  was  put,  aside  from  tool  grinding,  was  a  simple  kind  of 
surface  grinding  called  in  shop  language  "spot  grinding." 

This  operation,  while  comparatively  simple,  is  productive 
of  accurate  results  and  is  used  at  the  present  time  in  finishing 
certain  kinds  of  gauges  and  other  work  where  extreme 
accuracy  as  regards  parallelism  is  desired.  The  operation 
is  illustrated  in  Fig.  61.  The  operator  is  grinding  a  die  by 
passing  the  work  back  and  forth  under  the  wheel.  If  the 
plane  upon  which  the  work  slides  is  a  flat  surface,  it  follows, 
that  true  planes  will  be  ground  on  the  work. 

Fig.  62  illustrates  a  set  of  accurate  size  blocks  as  used  by 
tool-makers  and  machinists  who  work  to  close  limits.  After 
hardening,  gauges  of  this  kind  are  often  finished  parallel 
by  spot  grinding,  leaving  a  very  small  amount  for  final 
lapping  on  each  surface.  The  amount  left  for  the  final 
finishing  is  generally  0.0002  inch  on  each  surface. 

At  the  top  of  the  illustration  is  shown  the  fixture  used  for 
holding  the  blocks  while  grinding.  This  consists  of  a  flat 
base  equipped  with  two  pinch  clamps  for  firmly  holding  the 
work  and  forcing  it  downward  at  the  same  time.  The  slat 

176 


SURFACE  GRINDING 


Fig.  61. — Spot-grinding  a  blanking  die. 


A0BML 

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Fig.  62. — Accurate  size  blocks  finished  by  spot  grinding  and  fixture  for 
holding  them  in  the  grinding  operation. 


ABRASIVES  AND  ABRASIVE  WHEELS 

seen  at  the  front  is  for  the  accommodation  of  the  micrometer 
so  that  the  operator  can  measure  the  work  without  taking 
it  out  of  the  fixture. 

Fig.  63  illustrates  a  tool-maker's  square,  the  base  of  which 
was  finished  by  spot  grinding.  The  wheel  marks  are  plainly 
seen  on  the  work.  The  wheel  marks  left  by  this  process 
are  very  slight  and  a  true  surface  is  assured  if  the  operator 
takes  time  enough  to  pass  all  parts  of  the  surface  under  the 


Fig.  63. — Spot-ground  tool-maker's  square. 

wheel  several  times,  in  fact  until  the  wheel  sparks  but 
faintly.  In  Fig.  64  is  shown  a  cylinder  and  steam  chest  for  a 
model  marine  engine.  The  top  of  the  cylinder,  the  top  and 
bottom  surfaces  of  the  steam  chest  and  the  under  surface  of 
the  steam  chest  cover  were  finished  by  spot  grinding  with 
the  object  of  making  a  steam-tight  joint  without  using 
packing. 

The  few  illustrations  shown  will  bring  to  the  mind  of 
the  practical  mechanic  numerous  instances  where  spot 
grinding  can  be  used  on  work  where  accurate  surfaces  are 
necessary.  The  process  is  simple  and  can  be  carried  out  on 
any  machine  equipped  with  a  grinding  wheel  and  a  table. 
The  wheels  used  for  this  operation  should  be  medium  soft 
in  grade.  The  grit  used  depends  on  the  finish  desired. 
For  die  grinding,  as  shown  in  Fig.  61,  a  grit  as  coarse  as  36 

178 


SURFACE  GRINDING 

can  be  used,  while  for  size-block  grinding,  wheels  as  fine 
as  80  grit  give  good  results. 

Another  early  adaptation  of  surface  grinding  consisted  of 
finishing  locomotive  guide  bars  after  they  were  hardened. 
Formerly,  guide  bars  were  invariably  made  of  wrought  iron 
and  case  hardened  to  insure  them  against  wear.  As  may 


Fig.  64. — Cylinder  and  steam  chest  for  model  engine  on  which  the  flat  sur- 
faces were  finished  by  spot  grinding. 

be  imagined,  these  pieces  were  often  sprung  in  hardening, 
thus  means  were  sought  for  correcting  this  error. 

An  early-developed  machine  for  guide-bar  finishing  is 
shown  in  Fig.  65.  This  is  not  a  grinding  machine  in  the 
strictest  sense  of  the  word  because  it  carries  a  circular  lead 
lap  instead  of  a  grinding  wheel.  The  work  is  securely 
held  by  the  clamps  shown  on  the  platen  and  automatically 
fed  back  and  forth  past  the  circular  lap  which  is  charged 
with  emery  or  other  abrasive  material.  The  roll  seen  at  the 
extreme  right  of  the  platen  is  for  the  purpose  of  charging 
the  lap. 

The  slide  that  carries  the  lap  spindle  is  actuated  by 
means  of  the  handwheel  which  is  plainly  shown,  while  the 
wedge  seen  under  the  lap-slide  ways  is  for  the  purpose  of 
setting  the  lap  square  with  the  work.  Lapping  guide  bars 
is  a  slow  operation  at  best,  but  it  is  productive  of  excellent 
results. 

Of  late  years,  machines  of  this  type  have  been  equipped 
with  grinding  wheels  in  place  of  the  lead  lap.  The  writer 

179 


ABRASIVES  AND  ABRASIVE  WHEELS 

observed  such  a  machine  modified  in  this  manner  at  the 
Baldwin  Locomotive  Works,  Philadelphia.  The  wheels  used 
were  Aloxite  in  shellac  bond. 

The  machine  just  described  is  the  forerunner  of  the  pres- 
ent-day face-grinding  machine,  or  side  surf acer  as  it  is  often 
called.  The  side  surfacer  was  first  extensively  used  for 
grinding  locomotive  guide  bars,  but  of  late  years  it  has  been 


Fig.  65. — Locomotive  guide-bar  lapping  machine. 

adapted  to  a  large  variety  of  surface-grinding  operations. 
A  modern  face-grinding  machine  is  illustrated  in  Fig.  66. 
This  machine  is  a  product  of  the  Diamond  Machine  Co., 
Providence,  R.  I.  It  carries  a  ring  wheel  30  inches  in 
diameter,  6  inches  wide  with  a  26-inch  hole.  This  gives  a 
working  surface  of  2  inches.  The  wheel  is  mounted  in  a 
substantial  chuck,  the  body  of  which  is  cast  iron;  turned 
all  over  to  insure  a  perfect  running  balance.  The  body 
of  the  chuck  is  tapered  on  the  outside  and  is  slotted  so  that 
it  may  be  readily  compressed  by  means  of  a  steel  ring 
which  is  drawn  up  on  the. taper  by  means  of  bolts.  The 
chuck  is  equipped  with  a  backing  plate,  back  of  the  wheel. 
The  object  of  the  backing  plate  is  to  bring  the  wheel  face 
forward  as  it  wears  away.  By  this  arrangement,  the  wheel 
can  be  used  down  to  a  thickness  of  1-1/4  inches  with  perfect 
safety.  Chucks  of  this  kind  also  insure  the  wheel  against 
flying  in  case  it  is  accidentally  fractured.  The  machine  is 
equipped  with  a  circulating  pump  which  floods  the  work 

180 


SURFACE   GRINDING 


with  water,  the  object  being  to  carry  away  dust  and  to 
keep  down  frictional  heat. 

The  operation  of  grinding  guide  bars  is  comparatively 
simple.     The  work  is  strapped  to  the  platen  of  the  machine 


Fig.  66. — Modern  face  grinding  machine  or  side  surfacer. 

as  shown  in  Fig.  67  and  automatically  fed  back  and  forth 
under  the  wheel  until  the  desired  finish  is  acquired. 

New  guide  bars,  as  they  come  from  the  planer,  are 
generally  finished  by  grinding  as  the  grinding  wheel  imparts 
a  smooth  surface  for  the  cross-head  gibs  to  slide  upon.  If 
the  work  is  planed  with  a  coarse  feed,  which  leaves  deep 
tool  marks,  so- much  the  better,  because  this  condition  helps 
to  keep  the  wheel  true  and  free  cutting. 

By  the  time  a  locomotive  comes  to  the  shop  for  a  general 
overhauling,  the  guide  bars  often  require  refinishing,  owing 
to  the  fact  that  the  pressure  brought  to  bear  on  them  through 
the  cross  heads,  by  the  action  of  the  main  rods,  wears  them 
out  of  a  true  plane.  This  wear,  in  some  cases,  is  as  great  as 

181 


ABRASIVES  AND  ABRASIVE  WHEELS 

1/32  inch.  They  are  carefully  lined  up  on  the  platen  of 
the  guide-bar  grinder  and  ground  until  the  wearing  surface 
presents  a  true  plane.  Guide-bar  grinding  is  one  of  the 
first  instances  where  the  grinding  wheel  showed  a  distinct 
saving  over  other  methods  in  the  railroad  shop. 

In  considering  side  surfacing  in  general,  it  should  be 
borne  in  mind  that  machines  of  this  type  cannot  "hog  of!" 
stock  as  rapidly  as  can  a  planer  or  miller.  On  certain  oper- 


Fig.  67. — Locomotive  guide  bar  in  position  for  grinding. 

ations,  however,  the  side  surfacer  shows  high  efficiency 
over  machines  equipped  with  cutting  tools. 

In  Fig.  68  is  shown  a  variety  of  work  that  is  admirably 
adapted  for  finishing  on  the  side  surfacer.  The  pieces  shown 
are  flasks,  flask  sides,  heads,  cases,  covers,  hoods,  lathe 
legs,  columns,  guards,  etc.  From  the  design  of  these  pieces, 
it  is  readily  seen  that  they  do  not  lend  themselves  readily 
to  milling  or  planing  operations.  It  is  on  work  of  this  kind 
that  the  side  surfacer  shows  efficiency.  In  finishing  work 
of  this  kind  on  the  miller  or  planer,  it  is  necessary  to  strap 
the  pieces  securely  in  place.  Pieces  of  comparatively  thin 
section  are  often  sprung  out  of  shape  by  this  procedure, 
caused  by  the  strains,  set  up  in  clamping,  adjusting  them- 
selves after  the  clamps  are  released. 

On  the  side  surfacer,  conditions  are  more  favorable  be- 
cause work  does  not  have  to  be  held  as  securely  for  grind- 
ing operations  as  it  does  when  it  is  to  be  finished  with 

182 


SURFACE  GRINDING 

cutting  tools.  Where  work  is  to  be  finished  regularly  on 
the  side  surfacer,  a  smaller  allowance  for  finishing  is  recom- 
mended which  causes  quite  an  annual  saving  in  metal  at 
the  foundry. 

A  rotary  grinding  fixture  designed  for  use  on  a  side 
surfacer  is  illustrated  in  Fig.  69.  This  is  a  self-contained 
unit  driven  by  a  3/4-horsepower  motor  running  at  a  speed 
of  i, 800  revolutions  a  minute.  Power  is  transmitted  to 


Fig.  68. — Type  of  pieces  readily  ground  on  the  side  surfacer. 

the  chuck  spindle  through  a  chain  drive  and  a  worm  and 
worm  wheel.  A  clutch  is  provided  to  throw  the  power  in 
or  out  and  a  crank  in  the  foreground  is  for  rotating  the 
spindle  by  hand,  as  occasion  requires. 

This  fixture  was  designed  for  finishing  work  that  here- 
tofore was  done  in  the  lathe  and  it  is  readily  seen  that  if 
the  fixture  is  properly  aligned  on  the  platen  of  the  machine, 
surfaces  that  are  square  with  the  spindle  of  the  attachment 
will  result.  Finishing  the  faces  of  round  work  by  this 
method  offers  the  advantage  of  combining  the  roughing 

183 


ABRASIVES  AND  ABRASIVE  WHEELS 

and  finishing  operations,  to  say  nothing  of  imparting  an 
excellent  finish. 

Side  surfacers  are  now  used  by  many  of  the  leading 
automobile  manufacturing  concerns  for  finishing  a  diversity 


Fig.  69. — Rotary  grinding  fixture  for  use  on  the  side  surfacer. 

of  pieces.  In  Fig.  70  is  shown  the  operation  of  facing 
gear-case  covers.  These  are  made  of  aluminum  and  3/32 
inch  is  allowed  for  finishing.  As  the  illustration  shows, 
four  covers  are  set  on  the  machine  at  one  setting,  being 
held  in  special  fixtures. 

184 


SURFACE  GRINDING 

An  interesting  grinding  operation  is  illustrated  in  Fig.  71. 
This  work  consists  of  finishing  aluminum  crank  cases  for 
airplane  engines.  The  work  is  clamped  in  special  fixtures 
and  1/8  inch  is  allowed  for  finishing.  The  surfaces  thus 


Fig.  70. — Finishing  gear-case  covers  on  the  side  surfacer. 

finished  require  no  scraping  and  in  assembling  they  are 
put  together  with  a  thin  paper  gasket  and  shellac. 

A  piece  difficult  to  machine  by  ordinary  methods  is 
illustrated  in  Fig.  72.  This  is  a  gear-case  cover  used  on 
tractors.  It  is  held  in  the  fixture  shown  and  rapidly  finished 
in  a  satisfactory  manner. 

To  successfully  finish  work  on  the  side  surfacer  is  not  a 
difficult  operation  if  the  operator  pays  due  attention  to  a 
few  simple  factors.  The  wheel  should  be  run  at  the  speed 
recommended  by  the  grinding-machine  manufacturer.  In 
the  case  of  the  3o-inch  wheel  on  the  machine  shown  in 
Fig.  66,  the  correct  speed  is  500  revolutions  per  minute. 
Plenty  of  water  should  be  used  as  this  keeps  down  the 
frictional  heat  and  aids  materially  in  imparting  a  good 
finish.  Also,  the  wheel  should  be  kept  "sharp"  by  frequent 

185 


ABRASIVES  AND  ABRASIVE  WHEELS 


Fig.  71. — Surfacing  airplane  engine-crank  cases  on  the  side  surfacer. 


Fig.  72. — Grinding  a  gear-case  cover  on  the  side  surfacer. 
186 


SURFACE   GRINDING 

dressing,  preferably  with  an  ordinary  wheel  dresser  of  the 
star- wheel  variety.  The  correct  table  speed  for  side  sur- 
facing depends  on  the  amount  of  material  to  be  removed. 
The  machine  illustrated  in  Fig.  66  is  equipped  with  three 
table  speeds  of  10,  17  and  22  feet  per  minute  respectively. 
A  slow  speed  should  be  used  when  taking  heavy  cuts,  other- 
wise the  wheel  is  not  given  a  chance  to  cut  properly.  In 
taking  light  finishing  cuts,  a  fast  table  speed  can  be  used  to 
advantage.  After  the  wheel  has  ceased  to  spark  heavily, 
it  is  a  good  plan  to  let  the  work  feed  past  the  wheel  several 
times  without  further  cross  feeding,  especially  with  work 
of  comparatively  thin  section.  This  practice  produces 
accurate  results  as  any  undue  pressure  caused  by  the 
grinding-wheel  which  might  spring  the  work  is  automatically 
avoided. 

In  selecting  wheels  for  the  side  surfacer,  it  should  be 
borne  in  mind  that  no  one  wheel  can  be  depended  upon  to 
produce  efficient  results  on  all  classes  of  work.  Wheels 
made  of  carbide  of  silicon  abrasives  give  excellent  results 
for  the  surface  grinding  on  cast  iron,  but  they  cut  slowly 
and  cause  undue  heating  when  used  on  steel.  For  malleable 
iron,  steel  castings  or  pieces  made  of  machine  steel,  alumina 
abrasives  should  be  selected.  All  grinding-wheel  manufac- 
turers carry  wheels  in  stock  for  the  grinding  machines  in 
question,  but  in  ordering  wheels,  the  manufacturer  should 
state  clearly  for  what  purpose  and  under  what  conditions 
the  wheels  are  to  be  used.  This  information  enables  the 
grinding-wheel  manufacturer  to  make  the  proper  selection. 

DIE  GRINDING 

Die  grinding  is  one  of  the  earliest  and,  at  the  present  day, 
one  of  the  most  common  practices.  When  we  stop  to  con- 
sider the  numberless  articles  seen  in  the  home,  office,  and 
factory  that  are  the  products  of  punches  and  dies,  it  is 
readily  seen  that  die  grinding  is  a  very  important  branch 
of  present-day  machine-shop  practice. 

187 


ABRASIVES  AND  ABRASIVE  WHEELS 

As  previously  stated,  dies  are  often  ground  by  spot 
grinding  as  shown  in  Fig.  61  and  this  practice  produces 
good  results  where  the  die  grinding  is  of  an  intermittent 
nature.  The  wheel  used  for  this  work,  assuming  that  the 
die  is  made  of  hardened  steel,  should  be  made  of  an  alumina 
abrasive,  and  should  be  run  at  a  surface  speed  of  approxi- 
mately 5,000  feet  per  minute.  The  grade  should  be  medium 
soft  and,  for  ordinary  purposes,  36  grit  gives  good  results. 
Where  an  extra-nice  finish  is  desired,  on  small  dies  for 
example,  a  wheel  in  finer  grit  can  be  used  to  advantage. 

As  Fig.  6 1  shows,  the  work  is  ground  dry.  For  this 
reason,  the  cut  taken  is  generally  comparatively  light, 
about  o.ooi  inch.  The  work  seldom  becomes  unduly  heated 
owing  to  the  fact  that  the  platen  of  the  machine  absorbs 
the  heat  from  the  die  nearly  as  fast  as  it  is  generated. 
Punches  are  ground  in  the  same  manner  as  dies  with  the 
exception  that  they  must  be  held  in  a  special  holder  in 
cases  where  their  shanks  are  made  integral. 

The  use  of  the  machine  jusc  considered  is  somewhat 
limited,  as  it  produces  flat  planes  only,  whereas  many  kinds 
of  dies,  especially  those  used  for  punching  comparatively 
thick  metal,  should  be  ground  to  give  a  shearing  cut.  To 
accomplish  this  it  is  necessary,  from  a  practical  point  of 
view,  to  utilize  a  machine  on  which  the  work  can  be  firmly 
fastened  and  fed  back  and  forth  under  the  wheel. 

The  machine  illustrated  in  Fig.  73  is  a  Brown  &  Sharpe 
number  2  surface  grinder — a  machine  that  is  widely  used  for 
sharpening  dies  and  for  the  general  run  of  surface-grinding 
work.  It  will  accommodate  work  18  inches  long,  6  inches 
wide  and  9-1/2  inches  high  when  using  a  wheel  7  inches  in 
diameter.  The  longitudinal  travel  of  the  platen  is  controlled 
by  dogs  that  actuate  the  reversing  lever  and  the  platen 
saddle  can  be  fed  in  from  o.ooi  to  0.009  inch  at  each  reversal 
of  the  platen. 

The  simplest  manner  in  which  to  hold  a  die  for  grinding, 
in  cases  where  a  flat  surface  only  is  desired,  is  to  grip  it  in 
the  vise  with  which  the  machine  is  provided.  This  practice, 

188 


SURFACE   GRINDING 

however,  is  not  always  productive  of  the  best  results 
because  it  is  sometimes  almost  impossible  to  hold  the  work 
level  in  this  manner. 

For  this  reason,  many  mechanics  prefer  to  strap  the  die 
directly  to  the  platen  of  the  machine,  as  illustrated  in  Fig. 


Fig.  73. — Brown  &  Sharpe  automatic  surface  grinder. 

74.  If  the  bottom  of  the  die  is  ground  flat  after  hardening, 
it  is  obvious  that  this  surface  can  be  used  for  locating  in 
subsequent  grinding  operations  to  bring  about  accurate 
results.  In  Fig.  74,  A  is  the  die,  B  the  platen  of  the  surface 
grinder,  C  the  grinding  wheel,  D  the  straps  that  grip  the 
work,  and  E  the  backing  straps  against  which  the  straps  D 
bear.  The  straps  D  act  as  pinch  clamps  and  their  downward 
thrust  seats  the  die  firmly  against  the  platen  of  the  machine. 

189 


ABRASIVES  AND  ABRASIVE  WHEELS 

Where  comparatively  thick  metal  is  to  be  pierced,  it  is 
common  practice  to  shear  the  face  of  the  die  as  shown  in 
Fig.  75,  wherein  A  is  the  die,  B  the  punch,  and  C  the  metal 
to  be  pierced.  The  double  taper  imparted  to  the  face  of 


Fig.  74. — Holding  a  blanking  die  in  position  for  grinding. 

the  die  allows  it  to  cut  the  metal  with  a  shearing  action 
which  relieves  the  punch  press  of  considerable  strain. 

A  fixture  for  holding  dies  that  are  to  be  ground  with  a 
sheared  face  is  illustrated  in  Fig.  76.  This  consists  of  a 
base  casting  (A)  and  a  die  holder  (B).  The  holder  swivels  on 


n 


Fig-  75- — Blanking  die  with  a  sheared  face. 

the  pin  (C)  and  is  locked  in  the  desired  position  by  the  bolts 
(D).  One  of  the  lugs  on  the  base  is  graduated  in  degrees 
for  ready  setting  as  shown  at  (E).  The  recess  in  the  holder 
is  machined  at  an  angle  to  correspond  to  that  of  the  die 

190 


SURFACE   GRINDING 


which  facilitates  ready  setting.  This  fixture  is  easily  made 
by  any  tool-maker  of  ordinary  ability  and  its  use  saves  con- 
siderable time  that  is  usually  spent  in  setting  up  by  other 
methods. 

Punches  are  ground  in  the  same  manner  as  dies,  with  the 
exception  that  other  means  are  usually  employed  in  locating 
them  on  the  grinding  machine.  A  punch  that  is  set  in  a 
holder  having  a  flat  upper  surface,  the  upper  member  of 
a  sub-press  for  instance,  is  readily  ground  by  strapping 
it  directly  to  the  platen  of  the  grinding  machine.  Many 
punches,  however,  are  made  with  integral  taper  shanks, 


Fig.  76. — Fixture  for  holding  dies  while  grinding  sheared  faces. 

thus,  means  must  be  provided  for  locating  them.  The 
simplest  method  consists  of  a  square  block  of  cast  iron, 
generally  machined  all  over,  with  a  taper  hole  bored  through 
it  to  accommodate  the  punch  shank.  A  block  of  this  type 
is  illustrated  in  Fig.  77,  wherein  A  is  the  block,  B  the  punch 
to  be  ground,  C  the  grinding  wheel  and  D  the  straps  that 
hold  the  block  in  place  on  the  grinding -machine  platen. 
These  are  finger  straps  and  holes  are  drilled  in  the  block  to 
accommodate  them. 

By  referring  again  to  Fig.  75,  it  will  be  seen  that  the 
punch  will  punch  out  a  comparatively  flat  piece  as  its  cutting 
surface  is  flat,  while  the  stock  that  is  perforated  will  be 
distorted  to  a  certain  extent  by  the  action  of  the  die  face. 
In  some  instances,  wre  do  not  care  whether  the  punches  are 
flat  or  not,  as  in  perforating  operations  where  the  punchings 
constitute  the  scrap,  but  we  do  desire  to  preserve  a  flat 
surface  on  the  stock  that  is  perforated. 

191 


ABRASIVES  AND  ABRASIVE  WHEELS 

In  this  case,  the  punch  is  ground  to  give  the  shear  instead 
of  the  die.  The  lower  part  of  the  punch  holder  shown  in 
Fig.  77  is  machined  to  accommodate  the  fixture  shown  in 
Fig.  76.  This  is  for  the  purpose  of  grinding  sheared  faces 
on  punches,  the  punch  block  being  held  in  the  position 


i        r 

ifii 

i  A 

c& 

D        ^ 

—s—\             'r-.— 

C          .      D 

1              1 

1 

Fig.  77- — Fixture  for  holding  tapered-shank  punches  for  grinding. 

usually  occupied  by  the  dies,  and  the  base  of  the  fixture 
swiveled  to  impart  the  desired  shear  to  the  punch. 

Die  grinding  in  itself  is  a  comparatively  simple  operation 
that  does  not  call  for  the  services  of  a  skilled  tool -maker. 
As  a  matter  of  fact,  at  the  present  time,  die  grinding  is 
done  in  many  plants  by  women  who  do  not  pretend  to 
be  skilled  mechanics.  All  that  is  necessary  is  to  understand 
the  fundamental  principles  of  surface  grinding  and  to  exer- 
cise due  care  to  see  that  the  depth  of  cut  and  the  cross 
feed  is  not  heavy  enough  to  cause  the  wheel  to  burn  the 
edges  of  the  die. 

In  ordinary  die  grinding,  if  done  dry,  which  is  the  usual 
custom,  the  depth  of  cut  should  be  from  o.ooi  to  0.002  inch 
and  the  cross  feed  o.oio  inch  for  each  reversal  of  the  platen. 
This  is  a  general  rule. 

The  wheels  used  for  die  grinding  should  be  made  of 
alumina  abrasives  and  they  should  be  quite  soft  and  coarse. 

192 


SURFACE  GRINDING 

Grades  3,  4  and  5  in  the  writer's  proposed  grade  scale  are 
generally  furnished  in  grits  from  36  to  46. 

At  the  first  sign  of  glazing,  the  wheel  should  be  trued  with 
a  diamond  tool.  The  easiest  method  for  truing  the  wheel 
on  a  surface-grinding  machine  is  to  clamp  the  diamond 
tool  in  the  vise  with  which  the  machine  is  equipped,  and 
feed  the  diamond  past  the  wheel  by  means  of  the  cross 
feed. 

Die  grinding  is  sometimes  done  wet,  which  practice,  of 
course,  expedites  production  as  the  water  keeps  down  the 
f fictional  heat.  In  wet  grinding,  both  the  depth  of  cut  and 
the  amount  of  cross  feed  can  be  materially  increased.  The 
machine  illustrated  in  Fig.  73  can  be  equipped  with  a  wet- 
grinding  attachment  wherein  water  is  supplied  to  the  wheel 
by  means  of  a  special  wheel  guard,  through  piping,  by  a 
centrifugal  pump  immersed  in  a  tank  supported  by  a  bracket 
from  the  floor.  The  water  is  caught  by  a  work  tank  pro- 
vided with  a  hood  and  splash  guards  and  returned  to  a 
settling  pan  through  a  flexible  discharge  pipe. 

On  the  larger  types  of  surface-grinding  machines,  the  work 
should  'be  ground  wet  under  practically  all  conditions.  The 
reason  for  this  lies  in  the  fact  that  the  comparatively  large 
wheels  used  create  more  friction  in  proportion  than  do  smaller 
ones.  A  surface-grinding  machine  of  the  type  in  question 
having  provision  for  an  ample  water  supply,  is  illustrated 
in  Fig.  78.  Machines  of  this  type  give  excellent  results  on 
heavy  die  work  such  as  sections  of  large  blanking  dies, 
which,  owing  to  their  nature,  cannot  be  made  from  a  solid 
piece  of  steel,  and  for  grinding  large  sub-press  dies  such  as 
are  used  for  blanking  armature  discs.  These  large  surface- 
grinding  machines  give  economical  results  as  the  depth  of 
cut  and  the  traverse  feed  can  be  materially  increased  when 
compared  with  smaller  surface-grinding  machines.  This  is, 
of  course,  owing  to  the  heavier  construction  throughout  and 
also  to  the  fact  that  a  larger  wheel  is  used.  Surface  grinding 
in  general  was  given  a  decided  impetus  some  25  years  ago 
by  the  introduction  of  the  magnetic  chuck,  by  means  of 


ABRASIVES  AND  ABRASIVE  WHEELS 

which  flat  work  is  readily  located  for  grinding.  The  mag- 
netic chuck  offers  the  additional  advantage  of  holding  flat 
work  securely  without  danger  of  springing. 


Fig.  78. — Surface-grinding  machine  having  provision  for  wet  grinding. 

A  magnetic  chuck  made  by  the  Heald  Machine  Co.  is 
illustrated  in  Fig.  79.  It  has  a  working  surface  13  inches 
long  and  6  inches  wide,  and  is  equipped  with  vertical  ad- 
justable side  and  end  stops  for  locating  the  work.  These 
prevent  the  thrust  of  the  grinding  wheel  from  forcing  the 
work  off  the  chuck.  The  front  edge  of  the  working  surface 
is  provided  with  a  T  slot,  the  object  of  which  is  to  accom- 
modate stops,  fingers,  retainer  strips,  etc.,  according  to 
the  nature  of  the  work  handled. 

Figs.  80  and  81  illustrate  special  types  of  magnetic  chucks 
designed  by  the  Heald  Company.  The  one  shown  in  Fig. 
80  has  a  taper  base  which  is  adjustable  for  finishing  tapered 
work  such  as  keys,  wedges,  etc.  The  base  plate  is  pivoted 
at  the  left-hand  end  and  has  an  adjusting  screw,  clamping 

194 


SURFACE  GRINDING 


Fig-  79  — Heald  magnetic  chuck  for  use  on  the  surface  grinder. 


Fig.  80.— Heald  magnetic  chuck  with  adjustable  taper  base. 


Fig.  8l. — Heald  magnetic  chuck  with  adjustable  swivel  base. 
195 


ABRASIVES  AND  ABRASIVE  WHEELS 

bolt,  and  graduations  at  the  right-hand  end.  The  gradua- 
tions show  the  taper  in  degrees  and  in  inches  per  foot.  This 
chuck  is  also  provided  with  a  swivel  adjustment  for  grinding 
compound  angles. 

The  chuck  shown  in  Fig.  81  has  a  swivel  base,  the  axis  of 
which  runs  lengthwise  through  the  cencer  of  the  chuck. 
The  swivel  plate  is  provided  with  trunnions  which  are  clamped 
to  hold  the  chuck  at  the  angle  desired.  This  is  indicated 
by  graduations  at  the  right-hand  end.  The  base  plate  is 
in  one  casting  which  supports  the  chuck  at  both  ends. 
Thus  the  outfit  is  self-contained. 

Both  these  chucks  lend  themselves  admirably  to  a  diver- 
sity of  tool-room  and  other  work  which  otherwise  would 
require  special  fixtures  or  setting-up  devices. 

A  properly  designed  and  constructed  magnetic  chuck 
should  demagnetize  as  soon  as  the  current  is  turned  off, 
but  to  assist  in  the  removal  of  work  having  comparatively 


IFig.  82. — Demagnetizing  switch  for  use  with  magnetic  chucks. 

large  contact  surfaces,  a  demagnetizing  switch  is  of  great 
assistance.  This  is  due  to  the  fact  that  after  the  current 
is  turned  off,  the  work  retains  a  certain  amount  of  mag- 
netism. To  offset  and  neutralize  this  force,  a  demagnetizing 
switch  as  shown  in  Fig.  82  is  employed.  This  device  is 
fitted  at  one  end  with  contact  points  which  close  the  circuit 
and  magnetize  the  chuck  for  operation.  At  the  opposite 

196 


'SURFACE  GRINDING 


end,  it  is  provided  with  contact  points  having  a  reversing 
spring  for  demagnetizing  purposes.  By  throwing  the  handle 
to  the  left,  the  chuck  receives  the  current  permanently 
and  by  throwing  it  to  the  right,  making  only  an  instant's 
contact  between  the  blades  of  the  switch,  the  demagnetizing 
effect  is  produced.  After  this,  the  work  can  be  removed 
readily  from  the  face  of  the  chuck. 

AJ1  work  that  is  ground  on  a  magnetic  chuck  is  bound  to 
retain  a  smal1   amount  of  magnetism  which  often  proves 


Fig.  83. — Heald  demagnetizer. 

detrimental,  owing  to  the  fact  that  small  particles  of  metal 
are  thereby  attracted.  Magnetized  pieces  are  readily 
demagnetized  by  the  device  shown  in  Fig.  83.  The  steel 
plates  seen  at  the  top  of  the  case  are  the  poles  of  magnets 
contained  in  the  box.  These  electro-magnets  are  energized 
by  connecting  to  an  alternating-current  circuit.  The  rapid 
reversals  of  polarity  produced  by  this  kind  of  current, 
remove  all  traces  of  magnetism  by  simply  passing  the  work 
a  few  times  across  the  steel  plates. 

In  installing  and  operating  magnetic  chucks,  two  im- 
portant factors  should  be  borne  in  mind.  First,  the  voltage 
for  which  the  chuck  is  wound  should  correspond  to  the 
voltage  in  the  circuit  to  which  the  chuck  is  to  be  connected. 
If  the  voltage  in  the  line  is  too  high  for  the  chuck,  the  latter 
will  be  burned  out  and  if  the  voltage  is  too  low,  the  chuck 
will  not  retain  the  work. 

Second,  magnetic  chucks  cannot  be  operated  on  alternat- 
197 


ABRASIVES  AND  ABRASIVE  WHEELS 

ing  current  because  the  rapid  reversal  of  polarity  produced 
by  such  currents  gives  the  poles  or  magnets  of  the  chuck 
no  permanent  holding  power.  Thus,  in  cases  where  direct 
current  is  not  available,  it  should  be  generated  by  a  small 
generator  driven  by  the  line  shafting. 


Fig.  84. — Grinding  work  with  irregular  contour  on  the  surface  grinder. 

A  Brown  &  Sharpe  surface  grinder  equipped  with  a  mag- 
netic chuck  is  illustrated  in  Fig.  84.  It  is  seen  that  the 
pieces  ground  are  of  irregular  shape  and  it  is  on  work  of  this 
kind  in  particular  that  the  magnetic  chuck  shows  efficiency 
when  used  on  the  surface  grinder.  The  pieces  shown  enter 
into  the  construction  of  shoe  machinery,  which  is  very 

198 


SURFACE   GRINDING 

accurate  work.  These  pieces  are  cast  iron,  the  limit  of 
variation  allowed  being  0.0002.  The  wheel  used  in  this 
case  is  Carborundum  241  grit,  M  grade. 

The  ordinary  run  of  surface  grinding,  as  far  as  the  method 
of  procedure  is  concerned,  does  not  differ  materially  from 
die  grinding.  With  some  classes  of  surface  grinding,  how- 
ever (tool-room  work  for  an  illustration)  more  care  has  to 
be  exercised  to  insure  accuracy.  Accurate  surface  grinding 
on  machines  of  the  type  under  consideration,  depends  a 
great  deal  on  the  "sizing  power"  of  the  wheel. 

Let  it  be  assumed  that  a  tool-maker  grinds  a  piece  4  inches 
long  and  3  inches  wide,  locating  the  work  on  the  magnetic 
chuck.  He  rough  grinds  both  sides  with  a  fairly  coarse 
cross  feed  and  then  takes  a  finishing  cut  over  one  side  with 
a  finer  feed.  The  work  is  then  turned  over  and  a  finishing 
cut  taken  over  the  other  side.  If  the  wheel  is  sizing  prop- 
erly, that  is,  holding  its  shape  and  size,  within  close  limits, 
the  variation  in  the  work  should  be  very  slight.  In  many 
cases,  the  work  will  be  slightly  tapered  from  o.ooi  to  0.002 
inch  owing  to  the  fact  that  the  wheel  wore  away  gradually 
while  the  cut  was  being  taken. 

The  remedy  for  this  is  to  true  the  wheel  carefully  and  to 
see  that  a  very  slight  depth  of  cut  is  used  for  finishing,  not 
over  0.0005  inch.  If,  under  this  condition,  the  work  still 
finishes  tapered,  the  error  is  due  to  two  causes.  Either  the 
wheel  is  too  soft  or  it  is  run  at  too  low  a  peripheral  speed. 

With  machines  having  no  provision  for  increasing  the 
spindle  speed  as  the  wheel  wears  down,  wheels  often  ap- 
pear soft  after  they  are  half  worn  out  owing  to  the  fact 
that  the  peripheral  speed  is  lowered  considerably.  The 
remedy  in  this  case  is  to  discard  the  wheel  and  mount  a 
new  one  that  is  of  the  proper  size.  In  nine  cases  out  of 
ten,  the  new  wheel  will  be  found  to  size  in  a  satisfactory 
manner.  For  this  reason,  it  is  poor  economy  sometimes 
to  attempt  to  use  wheels  until  they  become  too  small. 

If  a  new  wheel  fails  to  hold  its  size  when  run  at  a  peripheral 
speed  of  5,000  feet  per  minute,  it  is  a  sign  that  it  is  too  soft. 

199 


ABRASIVES  AND  ABRASIVE  WHEELS 

In  accepting  this  statement  it  is  understood,  of  course, 
that  the  operator  uses  the  whole  face  of  the  wheel.  That 
is,  he  has  not  trued  away  part  of  it  with  the  diamond, 
which  practice,  for  some  unknown  reason,  is  followed  in 
some  shops. 

If  the  full  face  of  the  wheel  is  used  and  the  grade  seems 
too  soft,  the  remedy  is  to  substitute  a  wheel  one  half  or 
one  grade  harder  or  to  use  a  wheel  in  combination  grit. 
These  combination  grit  wheels  have  remarkable  sizing 
power  and  are  preferred  by  many  who  have  made  a  careful 
study  of  the  underlying  principles  of  grinding.  The  wheel 
used  on  the  machine  shown  in  Fig.  84  is  in  combination 
grit  with  24  grit  as  a  basis. 

If,  however,  too  hard  a  grade  is  used,  the  wheel  will 
soon  fill  up  and  may  burn  the  work.  If  the  work  appears 
unduly  hot,  so  hot  the  hand  cannot  be  held  upon  it,  it  is 
generally  a  sign  that  the  wheel  is  overheating.  In  some 
instances,  minute  black  spots  are  seen  on  the  work,  which 
is  a  sure  sign  of  burning.  • 

Some  operators  are  under  the  impression  that  a  fine-grain 
wheel  is  necessary  for  producing  a  smooth  finish.  This 
supposition,  however,  is  erroneous.  For  the  ordinary  run 
of  tool-room  surface  grinding,  46  grit  is  fine  enough  although 
wheels  as  fine  as  60  grit  are  sometimes  used  on  very  small 
work.  Fine  grit  wheels  cut  slow  and  for  this  reason  are 
not  econoiitical  in  the  long  run.  A  wheel  in  coarser  grit, 
with  its  full  face  utilized,  will  be  found  to  give  a  satisfactory 
finish  if  it  is  trued  properly. 

When  a  wheel  chatters,  the  cause  can  be  traced  to  two 
sources.  Either  the  wheel  is  too  hard  or  the  spindle  bear- 
ings are  loose.  Chattering  causes  a  wavy,  speckled  ap- 
pearance on  the  work,  readily  detected  by  any  mechanic. 
The  remedy  is,  first  to  take  up  any  slack  in  the  spindle 
bearings  and  if  chattering  is  still  in  evidence,  attention 
should  be  paid  to  the  grade  of  the  wheel. 

The  machine  shown  in  Fig.  85  represents  another  type 
of  surface  grinder.  It  is  a  product  of  the  HeaJd  Machine 


SURFACE   GRINDING 

Co.  and  is  called  a  ring  and  surface  grinder.  In  shop  lan- 
guage, however,  these  machines  are  generally  referred  to 
as  piston-ring  grinders,  owing  to  the  fact  that  .they  are 
widely  used  for  grinding  the  sides  of  piston  rings. 


Fig.  85. — Grinding  piston  rings  on  a  Heald  ring  and  surface  grinder. 

Briefly  described,  the  main  frame  of  the  machine  carries 
a  vertical  spindle  upon  which  a  magnetic  chuck  is  mounted. 
The  spindle  is  adjustable  up  and  down  to  accommodate 
and  size  different  thicknesses  of  work  and  is  provided 
with  micrometer  adjustment  for  close  setting.  The  upper 
part  of  the  main  frame  supports  a  cross  head  which  carries 
the  wheel  spindle.  A  novel  feature  of  this  machine  is  that 
an  adjustment  is  provided  to  enable  the  wheel  to  grind 
tapered  as  well  as  flat  surfaces.  This  adjustment  is  of 


ABRASIVES  AND  ABRASIVE  WHEELS 

great  value  in  grinding  such  work  as  milling  saws  which 
should  be  thinner  at  the  center  than  at  the  periphery  to 
give  the  proper  working  clearance. 

A  larger  machine  built  on  the  same  principle  is  shown  in 
Fig.  86.  As  the  illustration  shows,  this  machine  is  equipped 
for  wet  grinding.  These  machines  will  grind  any  kind  of 


Fig.  86. — Heald  rotary  surface  grinder  arranged  for  wet  grinding. 

flat  work  within  the  capacity  of  the  chucks,  but  are  especially 
adapted  for  finishing  round  work  such  as  piston  rings, 
thrust  collars,  milling  cutters,  etc. 

In  comparing  rotary  surface  grinders  with  surface  grind- 
ers of  the  reciprocating  type,  it  is  seen  that  in  the  former, 
the  wheel  covers  the  entire  surface  of  the  work  being  ground 
in  much  less  time  than  it  does  in  the  latter.  For  this  reason, 
the  sizing  power  of  the  wheel  is  materially  increased. 


SURFACE  GRINDING 

A  widely  used  type  of  grinding  machine  is  illustrated  in 
Fig.  87,  the  Pratt  &  Whitney  surface  grinder.  In  the 
language  of  the  practical  man,  however,  this  machine  is 
generally  spoken  of  as  a  vertical  surfacer.  It  furnishes  a 


Fig.  87. — Pratt  &  Whitney  surface  grinder  or  vertical  surfacer. 

ready  means  for  removing  stock  accurately  and  rapidly, 
not  only  on  the  regular  work  of  surface  grinding,  but  on 
roughing  operations  where  very  little  metal  has  to  be  re- 
moved. In  this  work,  it  replaces  the  milling  machine  and 
planer  to  some  extent. 

Briefly  described,  this  machine  consists  of  a  rigid  base, 
upon  which  the  platen  travels,  and  a  substantial  upright 
which  carries  the  wheel  spindle.  The  platen  has  a  longi- 
tudinal movement  only.  A  traverse  movement  is  unnec- 

203 


ABRASIVES  AND  ABRASIVE  WHEELS 

essary  owing  to  the  fact  that  the  diameter  of  the  wheel  used 
is  sufficient  to  cover  the  whole  width  of  the  platen. 

The  machine  carries  a  wheel  14  inches  in  diameter  with 
a  4-inch  face.  The  rim  is  1-1/4  inches  which  gives  a  11-1/2 
inch  hole.  The  wheel  is  mounted  in  a  special  holder, 
bedded  in  hot  shellac  and  held  securely  by  means  of  clamps. 
The  wheel  speed  is  1,155  revolutions  a  minute. 

The  problem  of  locating  the  work  is  reduced  to  a  minimum 
owing  to  the  fact  that  the  machine  is  equipped  with  a 
magnetic  chuck.  By  means  of  rotary  chucks,  this  machine 
is  able  to  handle  both  plain  and  circular  grinding.  These 
chucks  are  made  both  magnetic  and  non-magnetic.  Non- 
magnetic chucks  are  used  for  locating  work  that  is  not 


n 


«    IB 


Fig.  88. — Plain  rotary  chuck  for  use  on  Pratt  &  Whitney  vertical  surfacer. 

attracted  by  magnetism,  such  as  bronze,  aluminum,  etc., 
while  magnetic  chucks  are  used  for  holding  pieces  made  of 
ferrous  metals.  A  plain  rotary  chuck  with  its  driving  mech- 
anism is  shown  in  Fig.  88.  The  base  upon  which  the 
chuck  revolves  is  clamped  to  the  platen  of  the  machine 
while  the  driving  mechanism  is  located  outside  the  water 
guard.  An  adjustment  is  provided  for  tilting  the  chuck, 
which  makes  possible  the  grinding  of  concave  or  convex 

204 


SURFACE  GRINDING 


surfaces.  The  duplex  and  quadruple  chucks  shown  in  Figs. 
89  and  90  are  used  on  production  work  where  they  increase 
the  output  materially.  The  duplex  chuck  is  adjustable 


Fig.  89. — Duplex  rotary  chuck  for  use  on  Pratt  &  Whitney  vertical  surfacer,. 

for  grinding  either  concave  or  convex,  but  the  quadruple 
chuck  does  not  possess  this  feature. 

Designed  for  a  production  machine,  the  grinder  in  ques- 
tion is  thoroughly  automatic.     The  table  is  provided  with 


Fig.  90. — Quadruple  rotary  chuck  for  use  on  Pratt  &  Whitney  vertical 
surfacer. 

two  feed  speeds  of  34  and  142  inches  per  minute.  The  feed, 
of  the  table  per  revolution  of  the  wheel  is  0.029  and  0.123^ 
inches. 

205 


ABRASIVES  AND  ABRASIVE  WHEELS 

An  endless  variety  of  flat  work,  both  rectangular  and 
circular,  can  be  finished  on  this  machine  as  shown  in  Fig.  91. 
The  pieces  shown  illustrate  blanking  dies,  thread-cutting 
dies,  ring  gauges,  chuck  bodies,  collars,  gears,  small-arms 
parts,  etc.  In  fact,  any  piece,  whether  hard  or  soft,  can  be 


Fig.  91. — Samples  of  work  finished  on  Pratt  &  Whitney  vertical  surfacer. 

finished  in  this  manner  if  its  surface  is  of  such  a  nature  as  to 
permit  gripping  on  the  magnetic  chuck. 

Successful  grinding  on  the  vertical  surfacer  depends  more 
on  the  selection  of  wheels  than  it  does  on  any  one  other 
factor.  Carbide  of  silicon  wheels  should  be  used  for  grind- 
ing cast  iron  while  alumina  abrasives  are  better  adapted 
for  steel — both  in  its  hard  and  soft  state.  A  factor  peculiar 
to  this  machine  is  that  the  width  of  surface  to  be  finished 
determines  the  grade  of  wheel  to  use.  Thus,  when  finishing 
comparatively  wide  surfaces  softer  wheels  are  necessary 
than  those  used  for  grinding  narrow  work.  The  following 
grits  and  grades  have  been  found  through  practical  experi- 
ment to  give  good  results.  On  cast-iron  and  aluminum 

206 


SURFACE  GRINDING 

grinding;  1 6  to  24  grit,  i  to  4  grade.  For  soft  steel;  16  to 
24  grit,  3  to  7  grade.  These  wheels  are  also  adapted  for 
malleable-iron  castings.  For  grinding  hardened-steel  parts 
1 6  to  24  grit,  i  to  4  grade  are  used.  These  gradings  are 
taken  from  the  writer's  grade  scale. 

To  grind  work  successfully  on  a  vertical  surfacer,  it 
must  be  borne  in  mind  that  one  wheel  cannot  be  expected 
to  show  efficient  results  on  all  classes  of  work;  and  for 
this  reason  several  wheels  for  various  purposes  should  in- 
variably be  kept  in  stock. 

In  grinding,  the  work  should  be  held  securely  on  the  chuck, 
otherwise  the  action  of  the  wheel  will  dislodge  it.  This 
sometimes  results  in  a  broken  wheel,  but  accidents  are 
readily  avoided  by  placing  backing  strips  around  the  work. 
The  face  of  the  chuck  should  be  cleaned  carefully  before 
placing  the  work  in  position,  if  accurate  results  are  required, 
because  a  small  amount  of  dirt  can  cause  an  error  of  several 
thousandths  of  an  inch. 

While  the  wheels  used  with  this  machine  are  very  free 
cutting,  owing  to  their  soft  grade,  they  should  not  be 
crowded.  That  is,  the  spindle  should  not  be  fed  down  too 
great  a  distance  at  each  reversal  of  the  platen.  To  ignore 
this  factor  is  to  invite  disaster  for  one  of  three  results  is 
bound  to  happen.  The  work  will  be  burned,  forced  off 
the  chuck  or  the  wheel  will  be  broken. 

The  wheel  must  be  kept  sharp  and  free  cutting.  It  is 
readily  trued  by  the  device  described  for  this  purpose  in 
Chapter  X.  An  expert  grinder  can  readily  detect  a  wheel 
that  needs  dressing  even  if  he  cannot  see  its  face.  A  wheel 
that  needs  dressing  overheats  the  work,  does  not  throw 
sparks  freely  and  leaves  a  polished  surface  on  the  work. 

Work  should  never  be  ground  dry  on  machines  of  this 
type.  A  liberal  supply  of  water  is  necessary  for  two  rea- 
sons: It  keeps  down  the  heat  caused  by  the  cutting  action 
of  the  wheel  and  it  also  carries  away  the  metal  particles 
removed  from  the  work.  Soda  water  supplied  by  the  cir- 
culating pump  should  be  used  as  plain  water  rusts  both  the 

207 


ABRASIVES  AND  ABRASIVE  WHEELS 


machine  and  the  work.  If  the  machine  is  used  intermit- 
tently, it  should  be  cleaned  thoroughly  after  using  and  oiled 
each  time  before  starting  up,  while  a  machine  that  is  used 
constantly  should  be  oiled  every  day  and  cleaned  thoroughly 
at  least  once  a  week. 

Another  type  of  surface-grinding  machine  is  illustrated 
in  Fig.  92.  This  machine  is  made  by  the  Blanchard  Machine 
Co.,  Cambridge,  Mass..  and  is  called  a  high-power  vertical 


Fig.  92. — Blanchard  high-power  vertical  surface  grinder. 

surface  grinder.  The  initial  machine  of  this  type  was 
built  by  the  Blanchard  Company,  some  eight  years  ago, 
for  their  own  use.  The  machine  is  built  very  rigidly  to 
eliminate  vibration  and  consists  principally  of  a  base  carry- 
ing an  upright  on  which  the  wheel  head  is  mounted  and  a 
revolving  platen  on  which  the  work  is  held. 

The  wheel  spindle  on  the  machine  shown  is  driven  directly 
208 


SURFACE  GRINDING 

by  means  of  a  2o-horsepower  motor  although  these  machines 
can  be  arranged  for  belt  drive.  In  the  majority  of  cases, 
however,  the  direct  drive  is  to  be  preferred. 

The  wheel  used  is  a  plain  ring  without  flanges,  thus 
clamps  are  not  necessary  in  holding  it  in  place.  It  is  set 
in  a  cast-iron  ring  either  with  sulphur  or  Portland  cement. 
The  ring  that  carries  the  wheel  is  fastened  to  the  face  plate 
at  the  bottom  of  the  driving  spindle  by  means  of  six  screws. 
To  reinforce  the  wheel  in  guarding  it  against  possible  break- 
age, a  wire  banding  consisting  of  two  windings  1/2  inch  wide 
of  brass  wire  is  applied  to  the  outside. 

A  novel  and  valuable  feature  peculiar  to  this  machine  is 
the  three-point  column  support.  In  turning  out  flat  work 
of  uniform  thickness  it  is  essential  that  the  wheel  spindle 
be  exactly  square  with  the  chuck.  While  this  alignment 
may  be  correct  when  the  machine  is  new,  it  does  not  follow 
that  any  wear  that  may  develop  will  be  uniform.  To  cor- 
rect errors  due  to  wear,  the  three-point  support  is  adjustable,- 
which  feature  makes  possible  correct  alignment  at  all  times. 
This  adjustment  also  furnishes  a  convenient  means  for 
setting  the  machine  to  grind  concave  or  convex  surfaces. 

The  work  to  be  ground  is  held  either  magnetically  or 
by  clamps  or  by  its  own  weight  on  the  rotary  chuck.  The 
table  body  on  which  the  chuck  is  mounted  slides  on  the 
base  and  carries  the  chuck  under  the  wheel  where  it  is 
rotated  by  power  and  the  wheel  fed  down  gradually  until 
the  desired  amount  of  metal  is  removed.  Both  hand  and 
power  feeds  are  provided,  the  latter  having  a  wide  range 
of  feeds  with  automatic  stops  that  can  be  set  at  any  point. 

The  feed  mechanism  comprises  a  hand  crank,  a  graduated 
rachet  wheel  and  a  pawl  driven  from  the  chuck  motion 
and  arranged  to  feed  once  at  each  revolution  of  the  work. 
The  feed  is  very  sensitive  as  each  tooth  of  the  rachet  wheel 
represents  0.0002  inch.  The  graduations  on  the  wheel  in- 
dicating thousandths  of  an  inch  are  1/2  inch  apart. 

Work  on  this  machine  is  invariably  ground  wet  and  means 
are  provided  for  insuring  an  ample  supply  of  water  which  is 

209 


ABRASIVES  AND  ABRASIVE  WHEELS 


supplied  inside  the  wheel  while  guards  are  provided  to  pre- 
vent the  escape  of  spray  as  it  is  thrown  out  by  the  centrif- 
ugal action  of  the  wheel. 

An  idea  of  the  wide  range  of  work  that  can  be  handled 
on  the  machine  in  question  is  illustrated  in  Fig.  93.  Here 
are  included  over  one  hundred  different  machine  parts 


Fig-  93- — Samples  of  work  ground  on  Blanchard  high-power  vertical 
surface  grinder. 

comprising  units  of  fire-arms,  rings,  thrust  collars,  gears, 
connecting  rods,  flatirons,  etc. 

The  machine  is  simple  in  operation,  but  it  should  be  re- 
membered that  it  is  a  precision  machine  in  every  sense  of 
the  word.  All  the  bearings  should  be  oiled  once  a  day  and 
the  grease  cups  turned  daily  while  the  oil  gauges  should  be 
kept  filled  to  the  center  of  the  glass  at  all  times. 

The  solution  for  cooling  the  work  should  consist  of  a 
mixture  of  50  gallons  of  water,  one  to  two  quarts  of  cutting 
oil  and  three  to  five  pounds  of  sulphate  of  soda. 


SURFACE  GRINDING 

In  chucking  work,  the  center  of  the  chuck  should  be 
left  open  whenever  possible.  A  practical  method  is  to 
place  the  work  in  a  circle  around  the  chuck  leaving  an  eleven- 
inch  hole  in  the  center.  The  work  should  be  backed  up 
against  slipping  by  means  of  a  loose  steel  ring  placed  around 
the  outside  of  the  work.  This  point  is  important  and 
should  never  be  overlooked.  It  must  be  remembered  that 
each  piece  of  work,  to  insure  proper  holding,  must  span 
one  or  more  of  the  brass  rings  on  the  chuck  face.  Large 
pieces,  the  shape  of  which  prevents  the  use  of  rings,  should 
be  securely  blocked  to  prevent  sliding.  In  grinding  non- 
magnetic work,  care  must  be  exercised  to  block  or  clamp 
the  same  according  to  shape.  As  the  pressure  exerted  by 
the  wheel  is  always  downward,  danger  of  tilting  the  work 
is  reduced  to  a  minimum. 

Soft  wheels  that  wear  away  readily,  thus  constantly  ex- 
posing new  cutting  grains,  are  to  be  preferred  to  harder 
ones  that  require  constant  truing.  If  the  wheel  refuses  to 
cut  freely  and  glazes  or  burns,  the  remedy  can  be  found 
in  one  or  more  of  the  following  factors :  A  softer  and  coarser 
wheel  should  be  used,  more  feed  with  the  object  of  keeping 
the  wheel  in  cutting  condition  should  be  used,  the  width 
of  the  work  surface  of  the  wheel  should  be  reduced,  the 
face  of  the  wheel  should  be  roughened  with  a  star-wheel 
dresser,  and,  if  grinding  broad  surfaces,  the  amount  of  oil 
in  the  cooling  solution  should  be  reduced  or  left  out 
altogether.  The  wheel  speed  must  remain  at  1,000  revolu- 
tions a  minute  for  a  1 6-inch  wheel,  and  860  revolutions  a 
minute  for  an  1 8-inch  wheel. 

The  power  feed  should  be  used  in  preference  to  hand 
feeding.  An  average  feed  is  o.ooi  inch  for  each  revolution 
of  the  work,  but  under  some  conditions,  feeds  as  heavy  as 
0.002  and  even  0.003  have  been  successfully  used.  The 
makers  of  the  machine  state  that  ic  is  better  to  use  too 
much  rather  than  too  little  feed  as  fine  feeds  glaze  the  wheel 
readily. 

The  speed  of  the  chuck  should  be  from  13  to  17-1/2 


ABRASIVES  AND  ABRASIVE  WHEELS 

revolutions  a  minute  for  the  average  run  of  work.  This  can 
be  increased  if  a  comparatively  small  piece  chucked  near 
the  center  is  being  ground.  On  the  other  hand,  the  speed 
should  be  reduced  somewhat  when  grinding  work  that 
practically  covers  the  chuck.  To  impart  a  very  smooth 
finish,  the  chuck  speed  should  be  reduced  to  five  revolutions 
a  minute  for  the  last  few  turns. 

The  proper  method  of  operating  the  machine  is  first 
to  locate  the  work,  then  close  the  switch  and  try  the  work 
to  make  sure  that  it  holds.  Next,  with  the  wheel  high 
enough  to  clear  the  work,  the  chuck  is  removed  to  its  grind- 
ing position,  as  far  as  it  will  go  under  the  wheel.  The 
chuck  is  next  started  and  the  wheel  fed  down  by  hand  until 
it  starts  to  grind  the  work,  when  the  power  feed  should  be 
thrown  in.  The  wheel  should  be  raised  before  stopping  the 
chuck  or  changing  the  chuck  speed  and  the  chuck  should  be 
stopped  before  it  is  moved  from  under  the  wheel. 

The  selection  of  correct  wheels  for  vertical  grinding 
machines  should  not  be  done  haphazard  if  the  best  results 
are  desired.  Owing  to  the  comparatively  broad  contact 
between  the  wheel  and  the  work,  a  slight  change  in  the  grade 
of  wheel  often  causes  unsatisfactory  work.  In  this  respect, 
vertical  surface-grinding  machines  are  far  more  sensitive 
than  other  types  of  precision-grinding  machines.  The 
width  of  the  surface  to  be  ground  often  affects  the  wheel 
grading.  Thus,  narrow  surfaces  require  harder  wheels  than 
do  pieces  with  comparatively  wide  surfaces.  After  much 
experimentation,  the  Bl  an  chard  Machine  Co.  standardized 
the  following  wheel  list,  which  gives  the  kind  of  wheel  to- 
gether with  the  proper  grit  and  grade  to  use  for  various 
classes  of  work. 

To  provide  means  for  readily  measuring  the  work  without 
taking  it  off  the  chuck,  the  Blanchard  Company  developed 
the  continuous  reading  caliper  gauge  illustrated  in  Fig.  94. 
The  attachment  eliminates  much  of  the  time  consumed 
under  ordinary  conditions  when  the  work  is  stopped  for 
the  purpose  of  removing  a  piece  for  measurement  with 


SURFACE  GRINDING 


Material 

Width 
of 
Surface 

Finer 
Finish 
and 
Narrower 
Surfaces 

Best 
Wheel 
for 
Average 
Work 

Faster 
Cutting 
and 
Broader 
Surfaces 

Fi.-.er 
Finisii 
and 
Narrower 
Surfaces 

"^est 
Vv  aeel 
for 
Aveiage 
Work 

Faster 
Cutting 
and 
Broader 
Surfaces 

Norton  Crystolon 

American  Carbolite 

Cast 
Iron 

Narrow 

30  H 

24! 

30  H 

20  I 

Medium 

30  G 

24  H 

14  H 

20  H 

14  I 

Broad 

24  G 

14  H 

30  G 

20  G 

14  H 

Chilled 
Iron 

Narrow 

24  I 

20  I 

Medium 

24  H 

20  H 

Broad 

24  G 

30  G 

20  G 

— 

Narrow 

24! 

14  I 

20  I 

14! 

Medium 

24  H 

14  H 

20  H 

14  H 

Bioad 

30  G 

24  G 

30  G 

20  G 

Aluminum 

Narrow 

20  I 

Medium 

20  H 

Broad 

14  H 

• 

Norton  Silicate  No.  38  Alundum 

American  Silicate  Corundum 

Malleable 
Iron 

Narrow 

3824! 

24-iX 

Medium 

3824  H 

24-1 

Broad 

3830  G 

3824  G 

24-K 

Soft 
Steel 

Narrow 

3830  I 

3824! 

30-1 

24-  1  X 

Medium 

3830  H 

3824  H 

3814! 

30-1 

24-1 

14-1 

Broad 

3824  H 

3814! 

30-K 

24-K 

Steel 
Castings 

Narrow 

3824! 

30-1 

24-iX 

Medium 

3824  H 

3814! 

30-1 

24-1 

Broad 

383oG 

30-K 

24-K 

Hardened 
Carbon. 
Steel 

Narrow 

3846  H 

3830  H 

46-K 

30-1 

24-1 

Medium 

3830  G 

3824  H 

46-K 

30-J< 

24-K 

Broad 

3830  G 

3824  G 

30-K 

24-*A 

Hardened 
High-speed 
Steel 

Narrow 

3830  H 

30-1 

24-1 

Medium 

3830  G 

30-K 

24-K 

Broad 

3830  G 

38240 

30-K 

24-»i 

!    '  -  * 

WHEELS   FOR   BLANCHARD   SURFACE   GRINDER 

Rnisfd  to  July  10,  1918. 


2I3 


ABRASIVES  AND  ABRASIVE  WHEELS 

the  micrometer.  The  device  increases  the  operator's  con- 
fidence in  grinding  work  accurately  and  rapidly  as  he  does 
not  have  to  feel  his  way  toward  the  final  finish.  Thus, 
he  can  use  a  heavy  feed  until  the  last  thousandth  is  to  be 
removed. 

As  the  illustration  shows,  the  device  consists  of  an  upright 
and  bracket  for  carrying  a  dial  indicator.    A  hardened-steel 


Fig.  94. — Continuous  reading  caliper  gauge  for  use  on  Blanchard  high-power 
vertical  surface  grinder. 

contact  point  rests  lightly  on  the  work  and  is  connected  by 
means  of  a  rod  to  the  gauge  head.  The  lower  face  of  the 
contact  point  is  of  a  flattened  cone  shape  and  as  its  vertical 
movement  is  slight,  it  readily  passes  over  openings  in  the 
surface  of  the  work  or  from  piece  to  piece. 

In  setting  the  gauge,  the  contact  point  is  brought  down 
on  a  size  block  or  a  finished  piece  of  the  desired  size  which 

214 


SURFACE  GRINDING 

is  placed  on  the  chuck  and  the  dial  of  the  gauge  is  revolved 
to  bring  the  zero  line  to  coincide  with  the  pointer.  The 
caliper  is  aligned  to  swing  the  contact  point  parallel  to  the 
surface  of  the  chuck  so  that  accurate  readings  can  be  taken 
at  any  convenient  place  on  the  work.  It  can  be  swung  out 
of  the  way  for  placing  or  removing  the  work  without  de- 
stroying its  setting. 

In  gauging  the  work,  the  caliper  is  swung  to  bring  the 
contact  point  over  the  work  while  it  is  being  ground.  Each 
piece  of  work,  as  it  is  carried  under  the  contact  point,  in- 
dicates on  the  dial  the  exact  amount  of  oversize  in  thou- 
sandths of  an  inch. 


CHAPTER  SEVENTEEN 

CYLINDRICAL   GRINDING 

Cylindrical  grinders — Operation  of  grinders — Driving  devices  for  work — 
Proper  wheel  speeds  for  various  metals  and  work — Traverse  feed — Depth 
of  cut — Roughing  and  finishing  cuts — Spark  ng — Backrest  and  steady- 
rests — Lubrication  of  work — Lubricating  compounds  and  mixtures — 
Dressing  and  truing  wjieels  while  on  the  grinder — Chatter  marks  and 
their  remedy — Selection  of  proper  wheels  for  use  on' cylindrical  grinders — 
Universal  grinders — Grinding  tapers — Various  operations  on  universal 
grinder. 

'T'HE  modern  cylindrical  grinder  is  one  of  the  greatest 
^  aids  to  rapid  production  as  it  furnishes  a  convenient 
and  accurate  means  for  finishing  a  large  variety  of  machine 
and  other  parts,  both  hard  and  soft.  Cylindrical  grinding 
is  a  trade  in  itself  involving  many  factors  that  are  intelli- 
gently understood  only  after  many  years  of  actual  practice 
and  patient  experimentation.  To  be  sure,  any  man  who 
is  mechanically  inclined,  or  any  woman,  too,  for  that  mat- 
ter, can  be  taught  to  operate  a  cylindrical  grinder  in  a 
few  weeks'  time,  but  to  understand  thoroughly  the  many 
perplexing  problems  of  the  grinding  department  of  the 
average  plant  calls  for  knowledge  that  is  acquired  only 
through  long  practice. 

In  the  foregoing  chapter,  it  was  seen  that  there  are  many 
types  of  surface  grinders,  but  with  cylindrical  grinding  the 
types  of  machines  used  do  not  differ  materially  except  in 
one  major  point.  That  is  the  traverse  movement  of  the 
machine  which  carries  the  work  past  the  wheel.  The  oldest 
and  most  commonly  used  type  consists  of  a  stationary 
wheel  with  a  movable  platen  while  in  a  later  type  of  ma- 

216 


CYLINDRICAL  GRINDING 

chine,  the  platen  does  not  move  while  the  wheel  carriage 
does. 

As  to  the  most  efficient  type  there  is  a  question.  This 
has  never  been  settled,  even  among  abrasive  engineers. 
However,  both  types  give  excellent  results  in  actual  prac- 
tice. For  the  ordinary  run  of  work,  it  is  the  writer's  opinion 
that  one  type  is  as  efficient  as  the  other.  It  cannot  be 
denied,  however,  that  in  grinding  very  heavy  work  (pieces 
weighing  several  hundred  pounds)  the  traveling  wheel  offers 
a  decided  advantage,  as  the  frequent  reversal  of  motion  of 
a  unit  weighing  several  hundred  pounds  is  eliminated. 

Grinding  machines  of  the  types  before  mentioned,  that 
is  those  having  traveling  wheel  heads  and  those  having 


Fig-  95- — Landis  iox36-inch  plain  grinding  machine. 


traveling  platens,  are  again  divided  into  two  classes,  plain 
grinders  and  universal  grinders.  A  plain  grinder  is  a  ma- 
chine designed  to  take  the  place  of  the  engine  lathe  in 
finishing  all  kinds  of  turned  work  both  straight  and  tapered, 
provided  that  the  taper  is  not  too  abrupt.  A  universal 

217 


ABRASIVES  AND  ABRASIVE  WHEELS 

grinder,  as  its  name  indicates,  can  be  used  for  a  wide  range 
of  work  which  includes  besides  plain  grinding,  internal 
grinding,  face  grinding,  taper  grinding,  cutter  grinding  and 
in  some  cases,  surface  grinding.  In  the  strictest  sense  of  the 
word,  the  universal  grinder  is  not  a  production  machine 
and  its  usefulness  is  mostly  confined  to  the  tool-room. 

Figs.  95,  96,  97  and  98  represent  modern  plain  grinding 
machines  as  used  on  production  work.    The  machine  shown 


Fig.  96. — Landis  I2x96-inch  plain  grinding  machine. 

in  Fig.  95  is  a  10  x  3 6 -inch  plain  grinder  built  by  the  Landis 
Tool  Co.,  Waynesboro,  Pa.  It  is  thoroughly  automatic 
in  operation  as  regards  traverse  and  cross  feeds.  The  wheel 
carriage  on  this  machine  traverses  while  the  platen  is 
stationary.  The  reversal  can  be  set  at  any  desired  place 
to  suit  different  lengths  of  work  and  the  cross  feed  can 
be  set  to  feed  either  light  or  heavy  at  each  reversal  of  the 
wheel  carriage  and  also  to  cease  feeding  when  a  desired 
size  has  been  reached.  This  feature  is  of  great  value  in 
grinding  routine  work  as  the  "  cut-and-try "  method  is 
almost  wholly  eliminated.  The  work  is  driven  on  two  dead 
centers.  The  machine  illustrated  in  Fig.  96  is  also  a  product 
of  the  Landis  Company.  It  takes  work  up  to  12  inches  in 
diameter  and  96  inches  long.  Its  essential  features  are  the 
same  as  those  of  the  machine  shown  in  Fig.  95,  but  it  has 
an  additional  feature  that  is  a  decided  novelty,  the  double 

218 


CYLINDRICAL  GRINDING 

control  seen  at  the  front.  This  is  especially  valuable  in 
grinding  long  work  as  the  machine  can  be  fully  controlled 
from  either  station.  Both  of  the  Landis  grinders  shown 
are  arranged  for  individual  electric  drive. 

The  machine  illustrated  in  Fig.  97  is  a  10  x  36-inch  plain 
grinder,  arranged  for  belt  drive.    It  is  built  by  the  Norton 


Fig-  97- — Norton  iox36-inch  plain  grinding  machine. 

Grinding  Co.,  Worcester,  Mass.  In  this  type  of  grinder, 
the  wheel  is  stationary  while  the  platen,  which  carries  the 
head  and  tail  stock,  traverses.  This  is  also  a  production 
machine  and  it  is  entirely  automatic  in  operation.  Fig. 
98  shows  another  plain  grinder  built  by  the  Norton  Grinding 
Co.  It  is  a  much  larger  machine  than  the  one  shown  in 
Fig.  97,  but  it  operates  on  the  same  principles.  It  takes 
work  14  inches  in  diameter  and  72  inches  long.  There  are, 
of  course,  many  other  makes  of  plain  grinding  machines 
on  the  market,  but  they  all  work  on  the  same  basic  princip^s. 
That  is,  they  provide  means  for  holding  and  revolving 
the  work  to  be  ground  on  dead  centers,  means  for  auto- 

219 


ABRASIVES  AND  ABRASIVE  WHEELS 

matically  traversing  the  work  past  the  wheel,  or  vice  versa, 
and  means  for  actuating  and  controlling  the  cross  feed 
automatically. 

So  much  for  plain  grinding  machines.  Let  us  now  con- 
sider the  subject  of  cylindrical  grinding  itself.  To  permit 
the  grinding  machine  to  produce  its  maximum  output,  it 
is  necessary  to  pay  attention  to  the  manner  in  which  the 
work  is  prepared  for  the  grinder.  In  many  cases,  especially 
on  comparatively  small  work,  no  preparation  aside  from 


Fig.  98. — Norton  i4X72-inch  plain  grinding  machine. 

centering  and  squaring  up  the  ends  is  necessary.  This 
is  especially  true  in  cases  where  pieces  are  of  a  given  size 
for  their  whole  length,  in  which  case  the  material  is  often 
cold-rolled  steel  o.oio  oversize. 

With  the  majority  of  work,  however,  experience  has 
proven  that  one  roughing  cut  in  the  lathe  is  generally 
necessary.  The  rough  feed  marks  made  by  coarse-feed, 
high-speed  turning  aid  materially  in  the  grinding  operation 
as  they  help  to  keep  the  wheel  in  good  cutting  condition. 
When  a  rough  feed  is  used  for  turning,  1/32  inch  is  a  fair 
allowance  to  leave  for  grinding.  This  is  a  general  rule  and, 
of  course,  is  subject  to  modifications.  The  Landis  Tool  Co. 
has  compiled  a  table  of  grinding  allowances  for  work  run- 
ning in  diameter  from  1/2  to  12  inches  and  from  3  to  48 


CYLINDRICAL  GRINDING 

inches  long.     The  data  were  obtained  from  lengthy  experi- 
mentation and  the  table  follows : 

DIAMETER  LENGTH  IN  INCHES 

INCHES         3        6        9        12       15       18       24      30      36      42      48 

1/2 OIO  .OIO  .OIO  .OIO  .015  .015  .OI5  .O2O  .O2O  .O2O  .O2O 

3/4 oio  .010  .010  .010  .015  .015  .015  .020  .020  .020  .020 

i oio  .010  .010  .015  .015  .015  .015  .020  .020  .020  .020 

I-I/4 OIO  .010  .015  .015  .015  .015  .015  .020  .020  .020  .O2O 

I-I/2 OIO  .015  .015  .015  .015  .015  .020  .020  .020  .O2O  . O2O 

2 015  .015  .015  .015  .015  .020  .020  .020  .O2O  .O2O  .025 

2—1/4 OI5  -OIS  -015  -°i5  .020  .020  .020  .020  .020  .025  .025 

2-1/2 015  .015  .015  .020  .020  .020  . 02O  .O2O  .025  .025  .025 

3 015  .015  .020  .020  .020  .020  .C2O  .025  .025  .02$  .025 

3-1/2 015  .020  .020  .020  .020  .O2O  .025  .02$  .025  .025  .02$ 

4 020  .020  .020  .020  .020  .025  .025  .025  .025  .025  .030 

4—1/2 02O  .O2O  .O2O  .O2O  .025  .025  .025  .025  .025  .030  .030 

5 020  .020  .020  .025  .025  .025  .025  .025  .030  .030  .030 

6 020  .020  .025  .025  .025  .025  .025  .030  .030  .030  .030 

7 020  .025  .025  .025  .025  .025  .030  .030  .030  .030  .030 

8 025  .025  .025  .025  .025  .030  .030  .030  .030  .030  .030 

9 025  .025  .025  .025  .030  .030  .030  .030  .030  .030  .030 

10 025  .025  .025  .030  .030  .030  .030  .030  .030  .030  .030 

II 025  .025  .030  .030  .030  .030  .030  .030  .030  .030  .030 

12 030  .030  .030  .030  .030  .030  .030  .030  .030  .030  .030 

The  majority  of  pieces  that  are  to  be  finished  by  grinding 
are  driven  by  means  of  a  dog  placed  on  one  end.  The  dog 
engages  a  pin  that  projects  from  the  face  plate  of  the  head 
stock.  In  cases  where  it  is  advantageous  to  traverse  the 
entire  length  of  the  work  at  one  setting  (in  grinding  a  piece 
of  uniform  diameter  for  its  entire  length  for  an  illustration) 
the  driving  device  illustrated  in  Fig.  99  is  used  in  connection 
with  Brown  &  Sharpe  grinding  machines.  This  consists 
of  a  special  center  (B),  over  which  the  driver  (A)  revolves. 
The  driver  is  fastened  to  the  dead-center  pulley  by  the 
stud  68.  The  work  is  driven  by  the  two  pins  (C).  The  holes 
in  the  work  should  be  slightly  larger  than  the  pins  and 
they  should  be  drilled  by  means  of  a  simple  drilling  jig 
to  insure  their  slipping  over  the  pins  without  interference. 

Another  device  sometimes  used  is  a  square-shaped  center. 
In  this  case,  one  end  of  the  work  is  broached  to  fit  the 


ABRASIVES  AND  ABRASIVE  WHEELS 


center.  For  taking  comparatively  light  cuts,  this  method 
is  satisfactory,  but  it  possesses  one  disadvantage  in  that 
the  center  has  to  revolve,  getting  its  motion  from  the  head- 
stock  spindle.  However,  on  special  grinding  machines  such 
as  used  by  twist-drill  manufacturers,  this  type  of  center  is 


Fig-  99- — End  driving-dog  for  use  on  Brown  &  Sharpe  grinding  machines. 

often  used  as  an  inspection  of  the  centers  seen  in  some  makes 
of  twist  drills  shows. 

After  adjusting  the  tail  stock  to  suit  the  length  of  the 
work,  the  machine  must  be  set  to  grind  straight  by  adjust- 
ing the  swivel  on  the  platen.  In  theory,  this  should  not 
be  necessary.  In  actual  practice,  however,  it  is  found  that 
the  machine  has  to  be  "straightened  up"  every  time  the 
tail  stock  is  moved.  This  is  generally  caused  by  small 
particles  of  dirt  that  work  under  the  tail  stock.  It  is  a 
simple  matter  to  straighten  up  the  machine  as  all  that  is 
necessary  is  to  take  a  few  cuts  over  the  work,  caliper  to 
find  the  taper,  and  adjust  the  swivel  platen  to  offset  this. 

As  a  rule,  when  many  pieces  of  the  same  kind  are  to 
be  ground,  it  is  the  best  practice  to  make  two  grinding 
operations,  one  for  roughing  and  one  for  finishing.  In  the 


CYLINDRICAL  GRINDING 

roughing  operation,  the  wheel  should  be  kept  sharp  and 
free  cutting.  This  is  done  by  passing  the  diamond  past  it 
with  a  quick  motion.  From  o.ooi  to  0.005  should  be  left 
for  the  finish  grinding,  the  amount  depending  on  the  size 
of  the  work.  In  the  finishing  operation,  the  wheel  should 
be  carefully  trued  by  passing  the  diamond  over  it  with  a 
comparatively  slow  feed. 

Economical  and  efficient  cylindrical  grinding  depends  in 
a  great  measure  on  the  speed  at  which  the  wheel  is  run. 
No  hard  and  fast  rule  can  be  given- for  the  correct  wheel 
speed  as  it  can  range  anywhere  from  5,000  to  7,000  feet 
per  minute  surface  speed.  The  rule  is  to  slow  down  a 
wheel  that  shows  a  tendency  to  glaze  and  to  speed  up  a 
wheel  that  wears  away  too  readily.  A  little  attention  to 
this  rule  will  save  much  trouble  that  is  often  laid  to  the 
wheel. 

The  speed  at  which  the  work  is  rotated  has  much  to  do 
with  successful  cylindrical  grinding.  If  a  wheel  seems  to  be 
wearing  away  too  rapidly,  the  fault  can  be  overcome  in 
many  cases  by  reducing  the  work  speed.  On  the  other  hand, 
if  the  wheel  glazes  readily,  the  fault  is  often  overcome  by 
increasing  the  work  speed.  The  writer  does  not  hesitate 
to  state  that  it  is  impossible  to  lay  down  hard  and  fast 
rules  for  either  wheel  or  work  speeds.  The  skilful  operator 
gets  the  result  desired  by  a  combination  of  both.  The 
following  approximate  speeds,  however,  have  been  found 
to  be  satisfactory  under  general  conditions  in  cases  where 
the  grinding  wheel  was  run  at  a  peripheral  speed  of  5,000 
feet  per  minute. 

Cast-iron  roughing ". 40  feet  per  minute. 

Cast-iron  finishing 50  feet  per  minute. 

Steel  roughing 20  to  30  feet  per  minute. 

Steel  finishing 30  to  40  feet  per  minute. 

On  the  subject  of  work  speeds,  the  Landis  Tool  Co.  says: 
"Our  experience  is  that  a  surface  speed  of  30  to  60  feet  per 
minute  for  steel  and  cast  iron  gives  good  results.  However, 

223 


ABRASIVES  AND  ABRASIVE  WHEELS 

the  grade  of  the  material,  the  quality  of  finish  and  the  hard- 
ness of  the  wheel  must  be  considered  in  determining  the 
correct  speed.  Often  when  failure  to  produce  good  results 
is  attributed  to  the  wheel,  it  may  be  remedied  by  changing 
the  speed  of  the  work." 

The  traverse  speed  is  another  factor  that  must  be  con- 
sidered in  economical  grinding.  By  traverse  feed  is  meant 
the  distance  the  platen  travels  for  each  revolution  of  the 
work.  In  roughing  out  work,  this  traverse  should  be  very 
nearly  the  width  of  the  grinding  wheel  for  each  revolution 
of  the  work.  Thus,  if  a  wheel  with  a  2 -inch  face  is  used,  a 
traverse  feed  of  1-7/8  inches  will  be  satisfactory.  This 
practice  causes  the  wheel  to  wear  uniformly  inasmuch  as 
the  work  passes  the  wheel  with  a  decided  shearing  action 
which  helps  to  keep  the  wheel  true.  When  a  fine  finish  is 
required,  however,  the  traverse  feed  should  be  reduced  and 
the  work  speed  increased.  The  above  rules  apply  to  the 
general  grinding  of  steel.  In  grinding  cast  iron,  the  pro- 
cedure is  slightly  different.  For  the  rough  grinding  of 
this  material  a  narrow  traverse  feed  and  a  deep  cut  give 
better  results  than  a  wide  traverse  feed  with  a  slight  cut. 
In  finishing  cast  iron,  it  is  good  practice  to  make  as  few 
passes  over  the  work  as  possible  as  this  has  a  tendency  to 
prevent  wheel  glazing.  It  is  seen  that  this  is  in  direct 
opposition  to  the  generally  accepted  rule  for  finishing  steel, 
in  which  case  an  excellent  finish  is  obtained  by  letting  the 
work  traverse  back  and  forth  past  the  wheel  without  cross- 
feeding  until  sparks  are  hardly  visible.  In  shop  language 
this  operation  is  spoken  of  as  "grinding  out"  and  it  is  pro- 
ductive of  excellent  results,  even  when  a  comparatively 
coarse  wheel  is  used. 

To  find  the  speed  in  feet  per  minute  of  the  wheel  or  the 
work,  multiply  the  diameter  in  inches  by  3.14  and  the  result 
by  the  number  of  revolutions  per  minute;  then  divide  the 
product  by  12. 

The  depth  of  cut  is  understood  as  the  amount  the  work 
is  fed  toward  the  wheel  at  each  traverse.  In  cases  where  the 

224 


CYLINDRICAL   GRINDING 

work  to  be  ground  is  of  a  substantial  nature,  that  is,  com- 
paratively large  in  diameter  for  its  length,  a  heavy  cut 
can  be  taken;  in  fact  the  wheel  can  be  forced  into  the 
work  until  the  driving  belt  or  motor,  whichever  the  case 
may  be,  is  working  to  its  maximum  capacity.  This  rule, 
however,  applies  to  a  hand  feeding.  When  the  auto- 
matic feed  is  used,  a  sufficient  advance  at  each  reversal 
of  the  platen  should  be  made  to  keep  the  wheel  cutting 
at  its  maximum  capacity.  Heavy  cuts  in  roughing  opera- 
tions have  a  tendency  to  keep  the  wheel  true  and  in 
cutting  condition. 

Sometimes  in  taking  roughing  cuts,  it  is  noticed  that  the 
wheel  sparks  heavier  on  one  side  of  the  work  than  it  does 
on  the  other.  This  is  not  the  fault  of  the  machine,  but  is 
caused  by  the  internal  strains  and  forces  in  the  work  ad- 
justing themselves  or,  sometimes,  by  dirt  working  in  the 
centers.  It  is  needless  to  state  that  both  the  centers  on 
the  machine  and  in  the  work  should  be  cleaned  before  placing 
the  work  in  position  which  eliminates  this  cause  of  uneven 
sparking.  When  the  uneven  sparking  is  caused  by  the  work 
adjusting  itself  to  overcome  internal  strains,  the  evil  cor- 
rects itself.  The  machine  detects  and  corrects  the  error. 
When  the  work  sparks  uneven,  the  wheel  should  be  kept 
sharp  and  slight  feeds  used  until  the  work  sparks  evenly. 
A  slight  difference  in  sparking  often  leads  the  inexperienced 
operator  to  believe  that  the  work  is  badly  out  of  true.  This, 
however,  is  seldom  true,  for  in  many  cases  an  error  of  o.oooi 
inch  will  cause  uneven  sparking. 

To  secure  maximum  production  in  the  grinding  depart- 
ment, the  majority  of  pieces  that  are  ground  should  be  sup- 
ported in  the  grinding  machine  by  means  of  backrests  or 
steady-rests  as  they  are  also  termed.  A  visit  to  many 
grinding  departments  reveals  the  fact  that  this  rule  is  often 
neglected.  It  takes  a  little  time,  to  be  sure,  to  set  back- 
rests, but  the  results  obtained  by  their  use  amply  pay  for 
the  small  amount  of  time  consumed  in  setting  up.  There  is 
no  hard  and  fast  rule  for  the  number  of  backrests  to  use 

225 


ABRASIVES  AND  ABRASIVE  WHEELS 

on  a  given  piece  of  work.    One  rest  to  a  foot  is  sufficient, 
in  most  cases. 

Backrests  are  of  three  kinds:  solid,  spring  and  universal. 
A  difference  of  opinion  exists  among  grinding-machine 
manufacturers  as  to  what  is  the  most  efficient  type  of  back- 
rest, but  all  three  types  possess  certain  advantages.  A  solid 
backrest,  as  supplied  with  Norton  grinding  machines,  is 
illustrated  in  Fig.  100.  In  this  rest,  the  shoe  forms  a  cradle 
for  the  work  to  rest  in  with  a  saddle  or  bearing  point  dia- 


Fig.  100. — Plain  or  solid  backrest  for  Norton  grinding  machines. 

metrically  opposite  the  grinding,  wheel  and  another  on  the 
opposite  side  of  the  vertical  center  line  close  up  to  the  point 
where  the  wheel  comes  in  contact  with  the  work  being 
ground.  This  is  plainly  seen  in  the  illustration.  Howard 
W.  Dunbar,  in  Grits  and  Grinds,  a  Norton  Co.  publication, 
has  the  following  to  say  in  regard  to  solid  backrests: 

"The  shoe  should  be  exactly  the  same  diameter  as  the 
finished  ground  work,  and  should  be  allowed  to  come  in 
contact  with  the  surface  being  ground  immediately  upon 
starting  the  grinding  operation.  The  practice  of  attempting 
to  true  up  the  seat  for  the  steady-rest  shoe  before  bringing 
the  shoe  in  contact  with  the  work  is  wrong,  as  it  allows 
the  face  of  the  wheel  to  break  down,  due  to  vibration  of 
the  work  being  ground.  The  support  should  be  supplied 
immediately  upon  starting  the  grinding  operation.  It  is  a 

226 


CYLINDRICAL  GRINDING 

fact  that  work  can  be,  and  has  been  ground  round  and  true 
with  no  support  other  than  the  steady-rests." 
•    A  spring  backrest  made  by  the  Brown  &  Sharpe  Mfg.  Co. 
is  shown  in  Fig.  101,  and  the  following  description  of  this 
rest  and  its  use  is  from  Commercial  Grinding  by  the  Use  of 


Fig.  101. — Spring  backrest  for  Brown  &  Sharpe  grinding  machines. 

Plain  Grinding  Machines,  a  shop  handbook  published  by 
the  Brown  &  Sharpe  Mfg.  Co. : 

"The  shoe  is  of  wood,  brass  or  other  soft  metal,  the  end 
being  made  approximately  to  fit  the  work  being  ground. 
The  spring  keeps  the  shoe  in  close  contact  with  the  work 
and  also  allows  the  rest  to  conform  to  variations  in  the  size 
of  the  work.  The  work,  when  revolving,  tends  to  climb 
on  the  shoe,  thus  keeping  the  pressure  on  the  lower  roller 
and  supporting  the  work  on  the  under  side.  The  shoes 
should  be  made  of  brass,  soft  metal,  or  wood,  thus  allowing 
the  revolving  work  to  wear  the  surface  away  sufficiently 
for  it  to  fit  the  constantly  varying  size  of  the  work.  Brass 
or  soft  metal  is  best,  but  wood  is  also  used.  The  shoe  should 
have  sufficient  surface  to  last  well  but  not  enough  to  retard 
the  wear  mentioned.  The  shoe  should  move  freely  in  the 
slide  and  be  of  sufficient  mass  to  absorb  slight  vibrations. 
As  the  illustration  shows,  the  spring  holds  the  shoe  in  con- 
tact with  the  work  and  the  pressure  is  regulated  by  the 

227 


ABRASIVES  AND  ABRASIVE  WHEELS 

thumb  screw.  In  fitting  a  shoe  of  this  kind,  it  should  first 
bear  well  on  the  under  side  of  the  work.  The  wear  will 
quickly  fit  it  to  the  work  and  the  shoe  will  always  have  a 
firm  bearing  underneath.  The  shoes  should  never  be  made 
of  hard  metal  or  of  a  V  shape.  It  is  not  always  necessary 
for  the  shoe  of  a  spring  rest  to  bear  entirely  around  one- 
half  of  the  circumference  of  the  work.  A  shoe  of  sufficient 


Fig.  102. — Universal  backrest  for  Brown  &  Sharpe  grinding  machines. 

mass  will  prevent  vibration,  and,  as  it  is  of  soft  material, 
will  soon  wear  to  fit  the  varying  circumference." 

A  universal  backrest  is  illustrated  in  Fig.  102.  This 
device  is  a  product  of  the  Brown  &  Sharpe  Mfg.  Co.  and 
is  suitable  for  all  kinds  of  work.  It  possesses  the  advantages 
of  a  solid  rest  combined  with  those  of  the  spring  rest.  A 

228 


CYLINDRICAL  GRINDING 

Brown  &  Sharpe  grinding  machine  equipped  with  universal 
rests  is  illustrated  in  Fig.  103.  The  Brown  &  Sharpe  Com- 
pany give  the  following  directions  for  the  use  of  the  universal 
backrest : 

"One  rest  is  required  for  each  six  to  ten  diameters  of 
work  in  length.  Thus,  a  piece  of  work  i  inch  in  diameter 
and  36  inches  long  would  require  six  rests.  Shorter  work 


Fig.  103. — Brown  &  Sharpe  grinding  machine  equipped  with  universal 
backrests. 


having  different  diameters,  such  as  lathe  spindles,  require 
two  or  three  rests.  To  place  the  shoe  in  proper  position 
proceed  as  follows :  First,  select  shoes  the  size  of  the  finished 
work  and  hook  the  trunnions  25  into  the  Vees  26.  Second, 
turn  back  the  screw  27  far  enough  to  allow  the  shoe  to 
clear  the  work  and  loosen  nut  28  entirely  to  relieve  the 
pressure  on  spring  29.  Then  turn  back  screw  30.  Third, 
turn  forward  the  screw  3 1  until  a  light  pressure  is  given  to 
the  spring  32.  Turn  forward  the  screw  27  and,  if  the  spring 
29  is  wholly  relieved  and  the  screw  30  is  far  enough  back, 
the  shoe  will  come  in  contact  with  the  work  at  both  points 
A  and  B.  Fourth,  press  lightly  with  the  thumb,  on  36, 

229 


ABRASIVES  AND  ABRASIVE  WHEELS 

holding  the  shoe  in  gentle  contact  with  the  work,  and  turn 
the  screw  30  carefully,  noting  the  slightest  touch  of  the  end 
against  the  stop  C  in  order  that  none  of  the  parts  be  moved, 
and,  with  this  screw  in  contact  with  the  stop,  the  shoe 
should  bear  equally  at  both  points  A  and  B.  Turn  nut  28 
to  give  some  pressure  to  the  spring  29.  The  combined 
pressure  of  the  springs  29  and  32  should  be  only  sufficient 
to  resist  the  pressure  of  the  wheel  when  taking  the  last  cut, 
and  also  to  prevent  vibration  of  the  work  when  any  cut  is 
taken.  Constant  use  of  the  shoes  will  wear  the  surfaces 
A  and  B,  allowing  the  work  to  bear  on  that  part  of  the  shoe 
between  the  surfaces.  When  shoes  are  worn  in  this  man- 
ner, clearance  should  be  filed  between  the  surfaces  A  and  B. 
Fifth,  grind  the  trial  piece  of  work,  moving  the  screw  27 
to  maintain  the  contact  of  the  shoe  with  the  work  and  the 
screw  30  to  preserve  the  relative  diameters  at  the  various 
points.  As  the  work  approaches  the  finished  size,  measure 
at  the  different  rests  after  each  cut.  After  the  trial  piece 
is  finished,  with  the  diameter  alike  at  all  points,  the  shoe 
should  bear  equally  at  A  and  B  and  the  sliding  nut  33  should 
rest  against  the  shoulder.  Leave  the  parts  in  this  relation 
and  grind  the  other  piece  of  work,  adjusting  screw  27  only 
as  the  shoe  wears,  and  screw  30  for  the  delicate  adjustment 
for  diameter.  Note  the  effect  of  the  adjustment  upon  the 
sparks  to  determine  the  approximate  position.  When  the 
work  is  to  size,  the  nut  33  and  the  screw  30  are  intended  to 
rest  against  the  shoulder  and  stop  to  prevent  further  pres- 
sure of  the  shoe  upon  the  work.  The  shoe  and  wheel  will 
be  left  in  the  proper  position  for  sizing  duplicate  pieces. 
When  unground  work  is  placed  between  the  centers  and 
in  the  show  bearings,  the  nut  33  and  the  screw  30  will  be 
forced  away  from  the  shoulder  and  stop,  thus  compressing 
the  springs  29  and  32.  Should  the  shoe  bear  unequally 
at  A  and  B,  the  screw  28  should  be  tightened  to  increase 
pressure  at  A  and  screw  31  to  increase  pressure  at  B.  Do 
not  make  the  combined  pressure  of  these  springs  greater 
than  necessary  as  long  and  slender  work,  although  of  uni- 

230 


CYLINDRICAL  GRINDING 

form  diameter,  may  not  be  straight  when  released  from  the 
shoe  unless  some  allowance  is  made  for  elasticity." 

Some  twenty-five  years  ago,  when  grinding  machines 
were  few  and  far  between,  cylindrical  grinding  was  often 
done  dry.  This  practice  is  now  considered  unsatisfactory, 
except  perhaps  for  light  intermittent  work  as  sometimes 
done  in  the  tool-room  on  very  small  machines.  To  secure 
maximum  production  on  routine  work,  it  is  of  the  utmost 
importance  to  cool  and  lubricate  the  work  at  the  same  time. 
To  the  layman,  it  may  sound  out  of  place  to  speak  of  lubri- 
cating the  work  on  a.  plain  grinding  machine.  We  are  apt 
to  recall  the  all-round  machinist  of  a  quarter  of  a  century 
ago  who  would,  no  doubt,  hold  up  his  hands  in  horror  at  the 
thought  of  bringing  oil  in  contact  with  a  grinding  wheel. 

Various  compounds  are  now  used  in  lubricating  work 
while  grinding.  These  consist  of  mixtures  of  water,  soap, 
oil  and  sulphite  of  soda,  commonly  termed  sal  soda.  Plain 
water  is  sometimes  used  and  while  this  keeps  down  fric- 
tional  heat,  its  use  rusts  both  the  machine  and  the  work. 
Soda  water  is  better  than  plain  water  as  the  soda  prevents 
the  water  from  rusting.  The  various  compounds  put  up 
especially  for  the  purpose,  however,  are  efficient  as  they 
have  been  worked  out  by  grinding  engineers  after  much 
practical  experimentation.  The  lubricant  should  be  sup- 
plied by  the  circulating  pump  and  should  flood  the  work 
at  the  point  of  grinding  contact. 

To  produce  satisfactory  work,  it  is  necessary  that  the 
grinding  wheel  be  in  condition  to  perform  its  work  rapidly 
when  taking  roughing  cuts  and  smoothly  when  taking  finish- 
ing cuts.  A  satisfactory  cutting  surface  is  produced  on 
the  wheel  in  two  ways:  by  dressing  and  truing.  These  ex- 
pressions are  sometimes  confusing,  but  the  generally  ac- 
cepted meaning  is  that  dressing  consists  of  sharpening  a 
wheel  to  make  it  cut  fast,  while  truing  consists  of  imparting 
a  surface  that  will  leave  a  smooth  finish. 

As  explained  in  Chapter  X,  wheels  on  cylindrical  grinding 
machines  can  be  dressed  to  advantage  with  ordinary  star- 

231 


ABRASIVES  AND  ABRASIVE  WHEELS 

wheel  cutters  held  in  a  suitable  holder.  For  many  years, 
the  man  who  brought  an  emery-wheel  dresser,  as  this  tool 
is  called,  near  a  precision  grinding  machine  was  ridiculed, 
but  latter-day  experimentation  has  proven  that  grinding- 
wheel  dressers  of  the  Huntington  type  have  their  part  to 
play  in  cylindrical  grinding  as  well  as  for  dressing  wheels 
lor  rough  grinding  work. 

There  are  several  good  reasons  for  using  dressers  of  the 
kind  under  consideration,  not  the  least  of  them  being  the 
present  high  cost  of  the  bort  diamonds  generally  used  here- 
tofore. It  must  be  remembered,  however,  that  the  grinding- 
wheel  dresser  has  its  limitations.  On  the  cylindrical  grinder, 
its  usefulness  ends  in  preparing  wheels  for  roughing  oper- 
ations. To  true  the  face  of  the  wheel  for  taking  finishing 
cuts,  the  diamond  should  be  used. 

In  dressing  the  wheel,  the  dresser  should  be  held  in  a 
special  holder,  such  as  the  one  shown  in  Fig.  104,  which 
shows  a  special  Huntington  dresser  in  use  on  a  Norton 
grinding  machine,  and  fed  past  the  wheel  with  a  rapid, 
even  motion. 

In  truing  a  wheel  to  take  smooth  finishing  cuts,  the 
diamond  tool  should  be  held  securely  in  the  holder  provided 
ior  it  and  fed  past  the  wheel  with  an  even  motion,  taking 
.a  very  light  cut.  An  expert  operator  knows  how  to  use  a 
diamond  advantageously  to  bring  about  the  desired  results 
and  this  knowledge  is  gained  by  practice  alone.  In  both 
truing  and  dressing  operations,  the  wheel  should  be  flooded 
with  a  liberal  stream  of  lubricant. 

Chatter  marks  on  finished  work  are  sometimes  present 
and  they  can  be  attributed  to  a  number  of  causes.  Those 
not  thoroughly  conversant  with  the  art  of  cylindrical  grind- 
ing, often  lay  chatter  marks  to  the  gearing  in  the  headstock. 
It  is  true,  of  course,  that  incorrectly  fitted  gears  cause 
chatter  marks.  This  cause,  however,  is  not  of  common 
•occurrence.  The  unskilled  operator  who  desires  to  "wish" 
chatter  marks  on  the  headstock  gearing  generally  cites  the 
fact  that  an  incorrectly  fitted  rack  and  bull  gear  on  a  metal 

232 


CYLINDRICAL  GRINDING 

planer  leaves  marks  in  the  finished  work  and  thus  tries  to 
establish  a  parallel  case  with  the  grinder.  This  comparison 
is  not  logical.  The  planer  leaves  marks  in  the  finished  work 
because  the  gearing  is  allowed  to  bottom  either  through 
wear  in  the  ways  or  from  chips  and  dirt  that  become  im- 
bedded in  the  bottom  of  the  bull  gear  and  rack  teeth.  With 
the  grinder,  there  are  no  chips  or  dirt  to  work  into  the 


Fig.  104. — Dressing  the  wheel  on  a  Norton  grinding  machine  with  a 
Huntington  star-wheel  dresser. 

gearing  and,  furthermore,   wear  in  the  gears  in  question 
does  not  cause  them  to  bottom. 

Chattering  in  connection  with  the  plain  grinder  can  be 
laid  to  many  causes,  among  them  being  the  following: 
Centers  poorly  fitted,  wheel  slide  or  spindle  loose,  head  or 
tailstock  loose,  incorrect  relation  between  wheel  and  work 
speed,  lack  of  sufficient  steady-rests,  improperly  trued  wheel, 
wheel  out  of  balance  and  end  play  caused  by  the  work  not 
being  sufficiently  supported  by  the  centers.  When  chat- 

233 


ABRASIVES  AND  ABRASIVE    WHEELS 

tering  occurs,  the  first  thing  to  do  is  to  go  over  the  machine 
carefully,  inspecting  all  adjustments,  and  if  this  does  not 
correct  the  evil,  some  of  the  other  above-named  causes 
should  be  investigated. 

For  the  economical  and  efficient  operation  of  any  cylin- 
drical grinding  machine,  it  is  very  necessary  that  the  wheel 
be  in  as  perfect  running  balance  as  possible.  Wheels  that 
are  out  of  balance  cause  vibration  and  chatter  marks; 
they  wear  out  spindle  boxes  rapidly  and  if  badly  out  of 
balance,  they  are  liable  to  burst,  which  means  possible 
injury  to  the  workman,  the  loss  of  a  comparatively  ex- 
pensive wheel  and  curtailment  of  production  until  a  new 
wheel  is  mounted. 

Wheels,  as  they  come  from  the  grinding-wheel  manu- 
facturer, are  in  balance  within  very  close  limits.  It  is  im- 
possible for  the  wheel  manufacturer  to  make  a  wheel  that 


Fig.  105. — Balancing  a  grinding  wheel  by  chipping  the  heavy  side. 

is  in  perfect  running  balance  without  some  special  treat- 
ment owing  to  the  fact  that  the  wheel  texture  is  apt  to 
vary  slightly.  Thus,  one  side  of  the  wheel  may  be  a  little 
heavier  than  the  opposite  side. 

One  method  of  balancing  a  grinding  wheel  is  shown  in 
Fig.  105.    In  this  case,  the  light  side  of  the  wheel  is  at  A  and 

234 


CYLINDRICAL  GRINDING 


the  opposite,  or  heavy  side,  is  chipped  away  enough  to 
counterbalance  the  unequal  weight.  This  work  is  done  with 
an  ordinary  cold  chisel,  but  care  must  be  used,  otherwise 
the  wheel  will  be  broken.  The  Landis  Tool  Co.  make  use 
of  the  device  illustrated  in  Fig.  106.  This  consists  of  two 
balancing  blocks  which  have  radial  movement  in  a*i  annular 
groove  turned  in  the  wheel  holder.  The  blocks  can  be  se- 


Fig.  1 06. — Landis  wheel- holder  equipped  with  balancing  blocks. 

curely  clamped  in  the  desired  position  by  means  of  screws. 
It  is  a  comparatively  easy  matter  to  balance  a  wheel  that 
is  mounted  on  a  holder  of  this  type  as  all  that  is  necessary 
is  a  simple  adjustment  of  the  balancing  blocks. 

In  selecting  wheels  for  use  on  the  plain  cylindrical  grinder, 
it  must  be  borne  in  mind  that  rapid  production  depends  on 
the  wheel  used  more  than  it  does  on  any  one  other  factor. 
It  is  impossible  to  give  hard  and  fast  rules  governing  the 
selection  of  wheels  for  various  kinds  of  work  owing  to  the  fact 
that  local  conditions  often  have  to  be  taken  into  consider- 
ation. The  following  grits  and  grades,  however,  have  been 
found  to  give  satisfaction  for  the  various  classes  of  work 

235 


ABRASIVES  AND  ABRASIVE  WHEELS 


The  grades  are  given  in  the  writer's  proposed  grade 


listed, 
scale. 

MATERIAL 

Hard  Steel 

Soft  Steel 

Cast  Iron .  ; 

Brass 

Chilled  Iron 

Pistons,  Cast  Iron 

Pistons,  Steel 

Pistons,  Lyanite 

Piston  Rings,  Cast  Iron 


As  before  stated,  the  universal  grinder  is  adapted  to  a 
wide  range  of  work.  A  typical  universal  grinder  is  shown 
in  Fig.  107.  This  machine  is  made  by  the  Brown  &  Sharpe 


ABRASIVE 

GRIT 

GRADE 

Alumina 

30  to  40 

5  to  7 

Alumina 

30  to  40 

5  to  6 

Silicon  Carbide 

30  to  36 

4  to  7 

Silicon  Carbide 

30  to  40 

8 

Silicon  Carbide 

36 

8 

Silicon  Carbide 

24  to  36 

4  to  6 

Alumina 

24  to  36  ' 

4  to  6 

Silicon  Carbide 

30  to  40 

5  to  7 

Silicon  Carbide 

36  to  40 

4  to  6 

Fig.  107. — Brown  &  Sharpe  i2x3O-inch  universal  grinding  machine. 

Mfg.  Co.,  Providence,  R.  I.  The  average  universal  grinder 
is  somewhat  smaller  than  the  plain  grinder  ordinarily  seen. 
The  machine  illustrated  takes  work  30  inches  long  and  will 
swing  12  inches  over  the  platen  while  the  wheel  used  is  12 
inches  in  diameter  and  from  3/8  to  i  inch  thick. 

236 


CYLINDRICAL  GRINDING 

The  headstock  of  any  universal  grinder  is  supplied  with 
a  live  spindle  which  can  be  locked  when  it  is  desired  to 
grind  on  dead  centers.  The  live  spindle  adapts  itself  to 
a  variety  of  work,  principally  internal  grinding,  in  which 


Fig.-ioS. — Grinding  the -side  of  a  disc  on  a  Brown  &  Sharpe  universal 
grinding  machine. 

case  a  chuck  for  holding  the  work  is  screwed  on  the  nose 
of  the  spindle.  The  base  of  the  headstock  on  the  machine 
shown  swivels  and  this  permits  the  machine  to  handle  a 
variety  of  angular  work.  The  wheel  slide  also  swivels, 

237 


ABRASIVES  AND  ABRASIVE  WHEELS 

which  feature  is   often   taken   advantage   of  in   grinding 
abrupt  tapers  on  work  that  is  held  between  centers. 

The  following  examples,  which  graphically  illustrate  the 
adaptability  of  the  universal  grinder,  are  furnished  by  the 
Brown  &  Sharpe  Mfg.  Co.  Fig.  108  illustrates  the  grind- 
ing of  the  end  of  a  disk  that  is  fastened  to  a  shaft,  the  work 


Fig.  109.— Grinding  an  abrupt  taper  on  a  Brown  &  Sharpe  universal  grinding 
machine. 

being  held  between  centers.    The  grinding  wheel  is  placed 
on  the  end  of  the  spindle. 

In  Fig.  109  is  shown  the  operation  of  grinding  an  abrupt 
238 


CYLINDRICAL  GRINDING 

taper.  In  this  operation,  the  swivel  platen  remains  parallel 
with  the  ways  of  the  machine  as  in  plain  grinding,  but  the 
wheel  bed  is  set  to  the  required  angle  which  brings  the  line 
of  motion  of  the  wheel  slide,  when  operated  by  the  cross 
feed,  parallel  with  the  taper  to  be  ground.  The  wheel 


Fig.  1 10. — Grinding  two  tapers  at  one  setting  on  a  Brown  &  Sharpe 
universal  grinding  machine. 

platen  is  set  at  right  angles  with  the  line  of  movement  of 
the  wheel  slide,  indicated  by  the  arrow,  and  the  face  of  the 
wheel  is  thus  brought  parallel  with  the  line  of  the  desired 
taper.  The  work  is  revolved  by  the  dead-center  pulley  as 
the  illustration  shows,  and  the  wheel  is  traversed  over  the 
work  by  means  of  the  cross  feed. 

239 


ABRASIVES  AND  ABRASIVE  WHEELS 

It  is  often  advantageous  to  grind  two  tapers  with  one 
setting  of  the  machine  as  shown  in  Fig.  no.  The  Five- 
degree  taper  is  obtained  by  setting  over  the  swivel  plate 
while  the  forty-five-degree  taper  is  obtained  by  setting  the 
wheel  bed  to  the  desired  angle.  In  obtaining  the  angle  at 
which  the  wheel  bed  is  to  be  set,  after  the  swivel  platen 
has  been  set,  it  must  be  borne  in  mind  that  the  angle  must 
equal  the  sum  of  the  two  tapers.  The  abrupt  taper  is 
ground  by  feeding  the  wheel  across  the  work  by  hand, 
while  the  slight  taper  is  ground  by  feeding  the  platen  back 
and  forth  automatically. 

Fig.  in  shows  how  the  centers  are  ground  on  the  uni- 
versal grinder.  The  live  spindle  is  used  to  drive  the  center, 
the  headstock  being  swiveled  30  degrees. 


Fig.  ill. — Grinding  a  center  on  a  Brown  &  Sharpe  universal  grinding 
machine. 


An  interesting  operation  is  shown  in  Fig.  112  which  con- 
sists of  grinding  the  sides  of  such  work  as  hardened  collars, 
washers,  etc.  The  work  is  held  in  the  chuck  which  is 
screwed  to  the  nose  of  the  spindle,  while  the  headstock  is 
set  at  90  degrees  with  the  travel  of  the  platen.  The  wheel 

240 


CYLINDRICAL  GRINDING 


Fig.  1 12. — Grinding  the  side  of  a  disc  which  is  held  in  a  four- 
jaw  chuck  on  a  Brown  &  Sharpe  universal  grinding  machine. 


Fig.  113. — Appliance  for  grinding  the  sides  of  milling  cutters, 
discs,  etc.,  on  a  Brown  &  Sharpe  universal  grinding  machine. 

241 


ABRASIVES  AND  ABRASIVE  WHEELS 

is  brought  against  the  work  by  hand  feeding  and  the  auto- 
matic feed  is  used  to  traverse  the  work  past  the  wheel. 

For  grinding  such  work  as  washers,  milling  cutters,  thrust 
collars,  etc.,  the  appliance  illustrated  in  Fig.  113  is  conven- 
ient. The  face  plate  screws  on  the  end  of  the  spindle  and 
holds  the  work  by  means  of  a  split  bushing  which  is  ex- 
panded in  the  hole  in  the  work.  The  work  is  held  by  the 
expansion  bushing  C  which  is  expanded  by  the  screw  B 
and  drawn  tightly  against  the  face  plate  by  turning  the 
knob  A.  Different  sizes  of  bushings  are  readily  inserted 
to  take  care  of  a  wide  range  of  work. 

From  the  foregoing,  it  is  readily  seen  that  the  universal 
grinder  is  adapted  for  a  wide  range  of  work  that  cannot 
be  done  on  the  plain  grinder.  For  this  reason,  it  is  a  good 
plan  to  install  a  universal  grinder  in  cases  where  one  machine 
is  depended  upon  to  take  care  of  all  the  shop  needs.  Aside 
from  the  examples  shown,  the  universal  grinder  is  used  for 
internal  grinding  and  cutter  sharpening.  These  subjects 
will  be  treated  later. 


CHAPTER  EIGHTEEN 

INTERNAL   GRINDING 

Internal  grinding  machines — Internal  grinding  on  universal  grinder — Setting 
up  universal  grinder  for  internal  work — Grinding  double  tapers— Auto- 
matic grinders — Grinding  holes  in  spur  and  bevel  gears — Chucks — Wet 
and  dry  grinding — Proper  speeds — Selection  of  wheels — Operating  of 
cylinder  grinders — Cylinder  grinding. 

DEFORE  the  advent  of  the  automobile  industry,  in- 
•»— '  ternal  grinding  was  confined  chiefly  to  the  tool-room 
and  consisted  of  accurately  finishing  gauges,  bushings,  etc., 
the  work  being  done  on  the  universal  grinder.  With  the 
growth  of  the  automobile  industry,  however,  came  the  de- 
mand for  finishing  countless  numbers  of  parts  by  internal 
grinding  and  thus  special  machines  have  been  gradually 
developed  for  this  purpose. 

Special  internal  grinding  machines  are  production  tools 
just  as  the  plain  cylindrical  grinder  is  a  production  machine 
while  the  universal  grinder  is  still  used  for  the  internal 
grinding  of  general  tool-room  work. 

Fig.  114  shows  a  Brown  &  Sharpe  universal  grinder  ar- 
ranged for  internal  grinding.  Here  it  is  seen  that  the  regu- 
lar wheel  spindle  has  been  removed  and  in  its  place  sub- 
stituted a  jack  shaft  that  drives  the  internal  grinding 
fixture  which  is  bolted  to  the  wheel  platen.  It  is  also  seen 
that  the  wheel  spindle  bracket  is  reversed.  As  the  arrows 
show,  the  grinding-wheel  spindle  rotates  away  from  the 
operator  while  the  work  to  be  ground,  which  is  held  in  a 
chuck  screwed  to  the  nose  of  the  headstock  spindle,  rotates 
toward  the  operator. 

Setting  up  a  universal  grinder  for  internal  work  is  a 
simple  operation,  but  care  must  be  exercised  in  setting  the 

243 


ABRASIVES  AND  ABRASIVE  WHEELS 

headstock  to  bring  its  spindle  in  line  with  the  travel  of 
the  platen  if  parallel  work  is  desired.  It  is  almost  impossible 
to  accomplish  this  by  relying  on  the  graduations  of  the 
headstock  swivel  and  on  the  platen  swivel  and  as  the  cut- 


Fig.  114. — Brown  &  Sharpe  universal  grinding  machine  arranged  for 
internal  grinding. 

and-try  method  is  both  slow  and  uncertain,  other  means 
to  the  desired  end  are  generally  used  by  the  mechanic 
who  desires  to  turn  out  accurate  work. 

The  simplest  and  most  practical  method  for  accomplish- 
ing the  desired  result  that  has  come  to  the  writer's  notice, 
is  described  below :  First  the  chuck  is  screwed  on  the  head- 

244 


INTERNAL  GRINDING 

stock  spindle  which  is  unlocked  to  allow  it  to  rotate.  Next 
a  piece  of  round  stock  somewhat  longer  than  the  depth  of 
the  hole  to  be  ground  is  clamped  in  the  chuck  jaws,  allowing 
several  inches  to  project.  Then  a  relief  is  ground  close 
to  the  chuck  jaws.  This  is  for  the  grinding  wheel  to  dwell 
in  during  reversal  in  the  subsequent  operation.  Then  the 
outside  of  the  piece  is  ground  true  and  calipered  carefully 
and  the  headstock  reset  until  the  wheel  grinds  the  test 
piece  parallel.  When  parallelism  results,  it  is  evident  that 
the  headstock  spindle  is  parallel  with  the  travel  of  the 
platen,  which  is  the  situation  necessary  for  accurate  in- 
ternal grinding.  The  test  piece  is  now  removed  and  the 
machine  set  up  for  internal  grinding.  The  operator  need 
not  pay  attention  to  parallelism  after  this  as  it  is  assured. 
He  is  then  free  to  concentrate  his  efforts  to  getting  his  work 
to  the  desired  size. 

In  grinding  tapers,  the  headstock  is  set  over  to  the  desired 
angle  and  the  work,  after  being  ground,  is  tested  with  a 
taper  gauge  on  which  a  little  Prussian  blue  is  smeared. 
This  furnishes  a  ready  means  of  detecting  any  errors  that 
exist.  It  is  readily  seen  that  it  is  a  more  simple  matter  to 
set  up  the  internal  grinding  attachment  to  grind  tapers 
than  it  is  to  grind  absolutely  parallel,  that  is  by  the  cutting- 
and- trying  method. 

The  machine  shown  in  Fig.  115  is  arranged  to  grind  a 
double  taper.  The  swivel  platen  is  set  over  to  give  the 
five-degree  taper  while  the  wheel  platen  is  set  to  impart  the 
forty-five-degree  taper.  From  these  illustrations,  it  is  seen 
that  the  universal  grinder  can  be  adapted  to  a  variety  of 
tool-room  work.  In  fact,  it  can  handle  some  varieties  of 
work  that  are  beyond  the  range  of  the  production  internal 
grinder.  For  this  reason,  internal  grinding  on  the  universal 
grinder  will  always  be  a  part  of  tool-room  work. 

Special  internal  grinding  machines  are  designed  as  pro- 
duction tools  for  rapidly  and  accurately  finishing  more 
work  in  a  given  time  than  it  is  possible  to  turn  out  on  the 
universal  grinder.  Broadly  speaking,  these  machines  can 

245 


ABRASIVES  AND  ABRASIVE  WHEELS 

be  divided  into  two  groups,  those  having  hand  feed  and 
those  equipped  with  automatic  feed.  This  feature  applies 
to  the  platen. 

Machines   equipped   with  hand   feeds   are   adapted   for 
grinding   such   work   as   transmission   gears,    bevel   gears, 


Fig.  1 1 5. — Grinding  a  double  internal  taper  on  a  Brown  &  Sharpe  universal 
grinding  machine  set  up  for  internal  work. 

pinions,  bushings,  or,  in  fact,  any  kind  of  short  work.  Ex- 
perience has  proven  that  on  work  not  over  three  inches  long, 
the  average  operator  will  turn  out  more  work  with  a  hand- 
fed  machine  than  he  will  with  a  machine  equipped  with 
automatic  feed. 

The  machine  illustrated  in  Fig.  116  is  a  product  of  The 
Heald  Machine  Co.,  Worcester,  Mass.,  and  is  thoroughly 
automatic  in  all  its  operations.  It  swings  work  15  inches 
in  diameter  and  will  grind  holes  n  inches  deep.  The  head- 

246 


INTERNAL  GRINDING 

stock  is  swiveled  to  permit  grinding  taper  work  and  different 
speed  changes  are  provided  for  roughing  and  finishing 
operations.  The  cross  feed  is  automatic  in  operation  and 
can  be  set  to  release  when  a  given  size  has  been  reached. 
A  novel  feature  of  this  machine  is  the  protection  guard  over 
the  wheel.  This  comes  to  the  position  shown  in  the  illus- 


Fig.  116. — Heald  automatic  internal  grinding  machine. 

tration  when  the  platen  is  moved  away  from  the  work  and 
its  object  is  to  prevent  the  operator's  hand  from  coming 
in  contact  with  the  swiftly  revolving  wheel  should  his  hand 
slip  while  gauging  his  work. 

By  again  referring  to  Fig.  116,  it  is  seen  that  the  work 
is  held  in  a  three-jaw  chuck.  This  procedure  is  satisfactory 
in  cases  where  the  wall  of  the  bushing,  or  other  work  being 
operated  upon,  is  comparatively  thick.  With  thin-walled 
bushings,  the  pressure  brought  to  bear  by  the  chuck  jaws 
is  apt  to  cause  distortion  if  the  work  is  gripped  tight  enough 
to  hold  it  securely.  To  overcome  this  difficulty,  many 
novel  devices  have  been  originated.  One  of  these  is  shown 

247 


ABRASIVES  AND  ABRASIVE  WHEELS 

in  Fig.  117.  This  is  a  Heald  universal  bushing  chuck. 
It  consists  of  a  body  (i)  which  screws  on  the  spindle,  a 
movable  cap  (2),  and  adjustable  threaded  collar  (8),  and 
another  collar  (3)  which  centralizes  the  locating  plug  (4). 
The  bushing  to  be  ground  is  shown  at  5.  As  the  illustra- 


Fig.  117.— rHeald  universal  bushing  grinding  chuck. 

tion  shows,  the  part  of  the  plug  that  engages  the  bushing 
is  triangular  in  shape  (6),  while  the  end  that  engages  the 
threaded  collar  is  round  as  seen  at  7.  As  this  chuck  grips 
the  work  at  its  ends,  it  holds  it  securely  without  danger  of 
distortion. 

One  of  the  most  difficult  grinding  problems  with  which 
the  production  engineer  has  to  contend,  is  grinding  the 
holes  in  spur  and  bevel  gears  as  used  in  automobile  trans- 
missions and  differentials.  These  gears  are  hardened  and 
heat-treated,  thus  they  come  to  the  grinding  department 
in  a  slightly  distorted  condition.  For  smooth  running,  it 
is  obvious  that  the  pitch  line  of  the  gears  must  run  as  true 
as  possible  after  assembling.  To  this  end,  special  chucks 
have  been  developed  for  holding  these  gears  in  which  the 
location  is  taken  from  the  teeth  at  the  pitch-line  circle. 

Fig.  118  illustrates  three  common  methods  for  locating 
gears  as  described  by  the  Heald  Company.  In  A,  the  gear 
is  held  wholly  by  the  outside  diameter.  In  B,  jaws  of  special 
shape  are  employed,  which  grip  the  gear  at  the  bottom  of 
the  tooth  space,  while  in  C  rolls  are  used  which  make  con- 

248 


INTERNAL  GRINDING 


-3 


-C  I 


Fig.  1 1 8. — Three  types  of  chucks  used  in  grinding  the  holes  in  gears  on  a 
Heald  internal  grinding  machine. 


249 


ABRASIVES  AND  ABRASIVE  WHEELS 

tact  at  the  pitch  line.    The  first  and  third  methods  are  the 
ones  most  commonly  used. 

In  considering  the  first  method,  it  is  obvious  that  the 
outside  diameter  of  the  gear  is  not  always  concentric  with 
the  bore.  In  cases  where  the  outside  diameter  is  concentric 
with  the  bore,  the  teeth  are  often  eccentric  with  the  hole, 
owing  to  the  fact  that  the  gear  is  sometimes*  a  loose  fit  on 
the  gear-cutting  arbor.  Again,  the  gear-cutting  arbor  is 
often  slightly  out  of  true,  which  brings  about  the  same 
result. 

In  the  second  method,  shown  at  B,  the  jaws  of  the  chuck 
make  contact  at  the  bottom  of  the  tooth  space.  This  is 
a  better  method  than  the  one  above  described  inasmuch  as 
the  bottom  of  the  teeth  are  theoretically  all  the  same  dis- 
tance from  the  pitch  circle.  The  disadvantages  of  this 
method  of  locating  gears  is  that  the  bottom  of  the  teeth 
is  often  rough  and  sometimes  curved  owing  to  the  shape 
of  the  tooth  at  this  point  and  for  these  reasons  the  method 
is  not  as  satisfactory  as  it  might  appear. 

The  third  method,  shown  at  C,  called  pitch-line  control, 
wherein  the  gear  is  clamped  in  place  through  the  medium 
of  three  rolls  evenly  spaced  around  the  gear  as  the  illustra- 
tion shows.  If  the  teeth  are  evenly  spaced  and  the  gear 
unhardened,  this  method  is  generally  satisfactory.  It  must 
be  borne  in  mind,  however,  that  distortion  is  bound  to  take 
place  when  gears  are  hardened  and  this  has  an  effect  on 
the  spacing  of  the  gear  as  well  as  on  its  other  dimensions. 

It  is  readily  understood  that  any  variation  in  the  tooth 
spacing  is  bound  to  alter  the  even  spacing  of  the  rolls.  For 
example,  let  it  be  assumed  that  one  roll  is  located  in  a 
narrow  tooth  while  the  next  roll  happens  to  fall  into  a  wider 
tooth.  The  location  of  the  gear  is  bound  to  be  eccentric. 

The  chucks  shown  in  Fig.  118  are  all  alike  with  the  ex- 
ception of  the  locating  points  shown  at  4.  Briefly  described, 
the  chuck  consists  of  a  body  (2)  which  screws  to  the  nose 
of  the  spindle  and  a  collet  (3)  which  is  split  in  three  places 
and  drawn  into  the  chuck  by  means  of  a  drawing  rod 

250 


INTERNAL  GRINDING 


which  works  through  the  hole  in  the  grinding-machine  head 
spindle.  The  gear  is  shown  at  5,  while  6  is  the  grinding 
wheel  and  7  the  grinding-wheel  spindle.  The  body  of  the 
chuck  is  generally  made  of  cast  iron,  while  the  collet  is  steel 
and  insured  against  reasonable  wear  by  case  hardening. 

For  various  work,  aside  from  the  grinding  of  gears,  these 
collet  chucks  are  to  be  preferred  to  ordinary  three-jaw 
chucks  because  the  latter  soon  fill  up  with  particles  of 
metal  ground  from  the  work  which  calls  for  frequent  cleaning. 

For  grinding  gears  where  accuracy  and  quiet  running  are 
paramount  factors,  the  Heald  Company  have  developed 
the  chuck  shown  in  Fig.  119.  This  chuck  works  on  the 


Finish  for  Indicator 

.-Harafenecf  Spiff  King 


/Retainer  King 

Loose 
on  Rolls. 


Fig.  119. — Heald  multiple-roll  chuck  for  holding  gears  for  internal  grinding. 

multiple-roll  system  and  has  a  single  split  ring  which-  col- 
lapses as  it  is  forced  into  the  chuck.  In  this  method  of 
locating  gears,  a  number  of  rolls  are  used.  The  number 
depends  on  the  number  of  teeth  in  the  gear.  In  the  gear 
shown  in  the  chuck  in  Fig.  119,  nine  rolls  are  used.  The 
minimum  number  of  rolls  to  use,  however,  should  not  be 
less  than  five.  The  rolls  are  hardened  and  are  carried 
loosely  in  a  retainer  ring  which  keeps  them  in  the  proper 
position  and  in  shape  to  be  readily  handled  by  the  operator. 
In  Fig.  119,  the  gear  (7)  and  the  rolls  (6)  are  inserted  in  a 

251 


ABRASIVES  AND  ABRASIVE  WHEELS 

split  ring  (4)  made  straight  inside  and  tapering  on  the  out- 
side with  a  short  thread  to  enable  it  to  be  screwed  in  and 
out  of  the  body  of  the  chuck.  The  body  (3)  is  mounted 
on  a  face  plate  (2)  which  is  screwed  on  the  chuck  spindle  (i). 

The  object  of  making  the  chuck  body  in  two  pieces,  2 
and  3,  is  to  afford  ready  means  for  keeping  the  chuck 
running  absolutely  true.  By  referring  to  Fig.  119,  it  is 
seen  that  part  of  the  outside  of  the  piece  (3)  is  ground 
cylindrical  to  make  a  path  for  the  indicator  to  register  on 
while  truing  up  the  chuck.  This  feature  allows  the  operator 
to  check  up  the  running  of  the  chuck  as  frequently  as  de- 
sired. The  split  ring  (4)  is  hardened  to  insure  it  against 
wear.  Otherwise  the  pressure  of  the  rolls  would  soon  im- 
pair its  accuracy  as  they  would  imbed  themselves  slightly 
at  the  points  of  contact  every  time  the  chuck  was  tightened. 

In  Pig.  120,  is  shown  a  Heald  chuck  for  locating  large  bevel 
gears  as  used  in  automobile  rear  axles.  An  unhardened 


Fig.  1 20. — Heald  chuck  for  locating  large  bevel  gears  for  internal  grinding. 

gear  (2)  is  mounted  on  the  face  plate,  which  is  recessed 
slightly  to  center  the  locating  gear  so  that  it  will  run  true, 
at  all  times.  The  gear  to  be  ground  (3)  is  located  with  its 
face  to  the  locating  gear  and  is  held  in  place  by  three  clamps 

252 


INTERNAL  GRINDING 

shown  at  4.  As  the  illustration  shows,  a  portion  of  the  teeth 
of  the  locating  gear  are  cut  back  as  at  5  leaving  full-length 
teeth  (6)  at  three  points  of  the  circumference.  This  three- 
point  contact  insures  the  gear  against  rocking  on  its  seat. 

Another  novel  gear  chuck  is  shown  in  Fig.  121.  This 
chuck  was  originated  by  the  Heald  Company  and  is  used 
for  grinding  bevel  pinions.  In  reality  it  is  a  modification 


Fig.  121. — Heald  chuck  for  locating  bevel  pinions  for  internal  grinding. 

of  the  principle  used  in  the  chuck  shown  in  Fig.  119.  Taper 
rolls  are  used  which  are  spaced  around  the  circumference 
to  locate  the  gear  in  proper  position  according  to  the  pitch 
line.  The  taper  rolls  should  be  three,  five  or  seven  in  -num- 
ber, according  to  the  number  of  teeth  in  the  gear. 

The  method  of  holding  the  rolls  allows  for  a  certain 
amount  of  play  for  the  purpose  of  taking  care  of  slight 
variations  in  the  gears,  due  to  hardening. 

Referring  to  Fig.  121,1  is  the  spindle,  2  the  chuck  body,  3 
the  clamp  arms  that  hold  the  gear  in  position,  4  the  locating 
rolls  and  5  the  retaining  ring  in  which  the  rolls  are  mounted. 

While  the  present-day  internal  grinder  is  a  production 
machine  ia  every  sense  of  the  word,  it  is  not  a  tool  for 
"hogging"  off  stock.  It  is  a  machine  especially  designed 
for  finishing  operations.  For  this  reason,  attention  should 
be  paid  to  the  amount  of  stock  left  for  grinding,  especially 
in  hardened  work. 

253 


ABRASIVES  AND  ABRASIVE  WHEELS 

The  amount  to  be  left  for  grinding  depends  on  the  di- 
ameter of  the  hole  and  its  length.  In  considering  hardened 
work,  it  is  very  evident  that  comparatively  long  pieces  will 
warp  more  than  shorter  ones.  On  short  pieces  with  holes 
1-1/2  inches  in  diameter  and  down  to  i  inch,  0.008  to  o.oio 
inches  is  sufficient.  On  smaller  holes,  the  allowance  can 
be  decreased.  Larger  holes  require  a  more  liberal  allow- 
ance. A  good  plan  to  determine  the  amount  to  leave  for 
finishing  on  regular  production  is  to  start  with  liberal 
allowances  and  note  how  much  the  operator  has  left  to 
grind  out  after  the  work  has  been  ground  round,  that  is 
when  the  wheel  is  cutting  a  complete  circle  through  the 
entire  length  of  the  piece.  If  several  thousandths  of  an 
inch  are  invariably  left  to  remove  after  the  work  has  assumed 
a  round  and  true  shape,  the  grinding  allowance  can  be 
reduced. 

In  grinding  soft  work,  the  general  rule  is  to  leave  a  little 
more  than  is  absolutely  necessary  to  true  up  the  work  and 
grind  out  the  tool  marks.  A  little  experimentation  will 
determine  the  correct  amounts  in  all  cases. 

Internal  grinding  is  done  both  wet  and  dry.  The  general 
accepted  rule  is  to  grind  cast  iron  and  bronze  dry  and  to 
grind  steel  wet.  However,  this  rule  does  not  have  to  be 
adhered  to  without  exceptions  as  steel  is  often  ground  dry 
with  satisfactory  results.  In  wet  grinding,  the  hood  over 
the  chuck  keeps  the  spray  from  flying.  In  dry  grinding,  an 
exhaust  pipe  draws  away  the  dust  through  the  hollow-head 
spindle.  This  protects  the  operator  and  keeps  the  machine 
clean  at  the  same  time. 

Wheels  on  internal  grinders  are  run  at  peripheral  speeds 
ranging  from  4,000  to  6,000  feet  per  minute  while  the  work 
speed  can  vary  from  25  to  100  feet  per  minute.  There  is 
no  hard  and  fast  rule  to  refer  to,  but  the  experienced  oper- 
ator judges  the  correct  combination  of  wheel  and  work 
speed  by  the  quality  and  quantity  of  the  output  and  the 
performance  of  the  wheel. 

In  selecting  wheels  for  internal  grinding,  carbide  of  silicon 
254 


INTERNAL  GRINDING 

is  used  for  cast  iron  and  bronze  while  alumina  abrasives 
should  be  used  on  steel,  both  hard  and  soft.  For  the  aver- 
age run  of  work,  grits  from  36  to  50  are  used  in  grades  4  to  6 
on  the  writer's  grade  scale.  For  grinding  cast  iron,  the 
grades  are  somewhat  softer,  from  2  to  5.  As  a  general  rule, 
soft  wheels  give  the  best  results.  The  reason  for  this  lies 
in  the  fact  that  there  are  comparatively  few  cutting  points 
on  these  small  wheels,  and  if  they  do  not  wear  away  readily, 
bringing  new  cutting  points  into  action,  the  wheel  glazes 
quickly. 

Careful  attention  should  be  given  to  keeping  wheels  on 
internal  grinding  machines  true.  They  should  never,  under 
any  circumstances,  be  dressed  with  a  star-wheel  dresser 
although  a  carbide  of  silicon  brick  is  a  good  medium  to  use, 
provided  it  is  held  securely  in  a  holder  that  is  fastened  to 
the  platen  on  the  machine.  The  operator  should  never 
attempt  to  true  the  wheel  by  holding  the  brick  in  his  hand 
as  this  gives  poor  results.  The  diamond  is  an  ideal  tool 
for  truing  these  wheels,  but  the  present  cost  of  bort  stones 
makes  their  use  prohibitive  in  cases  where  another  medium 
will  serve  the  purpose  equally  well. 

Because  of  their  high  rotative  speed,  internal  grinding 
machine  wheel  spindles  should  be  properly  lubricated  with 
a  grade  of  oil  that  is  especially  adapted  for  the  purpose. 
There  is  a  great  difference  between  ordinary  slow-running 
bearings  and  those  of  a  high-speed  grinding  spindle.  The 
former  takes  a  heavy  oil  which  forms  a  thick  film  on  which 
the  journal  rests.  With  the  latter,  the  bearings  are  adjusted 
very  closely  and  for  this  reason  a  light-bodied,  high-grade 
oil  should  be  used. 

A  special  internal  grinding  machine  that  is  widely  used 
in  the  automobile  and  airplane  engine  industry  is  shown  in 
Fig.  122.  This  is  a  cylinder  grinder  made  by  the  Heald 
Machine  Co.  With  the  development  of  the  automobile 
industry,  considerable  difficulty  was  experienced  in  finish- 
ing cylinders  by  ordinary  methods,  that  is,  boring  or  ream- 
ing. This  was  due  to  several  factors,  chief  among  them 

255 


ABRASIVES  AND  ABRASIVE  WHEELS 

being  the  fact  that  cylinder  walls  are  comparatively  thin, 
thus  they  sprang  away  from  the  finishing  tools  which  left 
the  cylinder  considerably  out  of  true.  Again,  internal- 
combustion  engine  cylinders  should  be  made  of  a  compara- 
tively hard,  close-grained  iron  which  is  always  difficult  to 


Fig.  122. — Heald  cylinder  grinding  machine. 

machine  accurately.  With  these  factors  in  mind,  engineers 
turned  to  the  grinding  machine  for  a  solution  of  the  difficulty. 
The  ordinary  single  cylinder  of  other  days  was  a  difficult 
piece  to  grind  inasmuch  .as  it  could  not  be  rotated  readily 
— a  special  grinding  fixture  was  necessary  which  had  pro- 
vision for  running  and  balancing  each  individual  cylinder. 
Again,  it  would  be  impossible  to  rotate  a  cylinder  of  the 
type  illustrated,  in  Fig.  123,  which  is  cast  en  bloc.  There- 
fore the  machine  shown  in  Fig.  122  was  developed.  The 
base  and  upright  of  this  machine  are  cast  in  one  piece.  The 
wheel  spindle  is  mounted  at  the  top  of  the  upright  and  is 
of  the  planetary  type.  The  main  spindle  revolves  to  carry 

256 


INTERNAL  GRINDING 

the  wheel  around  the  wall  of  the  cylinder  to  be  ground 
while  the  supplementary  spindle  rotates  rapidly  to  impart 
motion  to  the  grinding  wheel.  A  special  adjustment, 
graduated  in  thousandths  of  an  inch,  determines  the  eccen- 
tric setting  of  the  wheel  spindle. 

The  platen  can  be  adjusted  at  right  angles  to  the  wheel 
spindle  by  means  of  a  screw  feed  equipped  with  a  microm- 


Fig.  123. — Multiple  cylinder  for  an  automobile  engine  as  finished  by 
grinding. 

eter  dial,  which  feature  is  made  use  of  in  grinding  cylinders 
of  the  type  shown  in  Fig.  123.  The  platen  is  fed  longi- 
tudinally by  means  of  an  automatic  feed,  the  movement 
being  controlled  by  adjustable  dogs  that  actuate  the  re- 
versal at  each  end  of  the  stroke. 

The  operation  of  grinding  the  cylinder  shown  in  Fig. 
123  is  shown  in  Fig.  124.  The  cylinder  is  mounted  on  a 
special  angle-iron  fixture  that  is  clamped  to  the  platen  of 
the  machine.  One  bore  of  the  cylinder  is  ground  at  a  time 
and  completely  finished  before  moving  the  platen  to  grind 
the  next  hole.  The  amount  to  leave  for  grinding  depends 
upon  the  size  of  the  cylinder  and  the  condition  in  which  the 
holes  are  left  by  the  rough  boring  operation.  Usually 
cylinders  are  rough  bored  with  a  coarse  feed  which  leaves 
deep  tool  marks.  This  is  advantageous  as  the  tool  marks 

257 


ABRASIVES  AND  ABRASIVE  WHEELS 

exert  a  shearing  motion  of  the  wheel  which  helps  to  keep 
it  true.  If  the  holes  are  accurately  spaced  in  the  boring 
operation  from  o.io  to  0.15  inches  below  the  bottom  of -the 
boring  tool  marks  are  sufficient  for  finishing.  This  is  not  a 
hard  and  fast  rule  by  any  means  as  local  conditions  must 
be  taken  into  consideration,  thus  experimentation  is  the 


Fig.  124. — Grinding  a  four-cylinder  unit  for  an  automobile  engine  on  a 
Heald  cylinder  grinding  machine. 

only  accurate  guide.  If  the  operator  finds  that  he  has  a 
large  amount  of  stock  to  remove  after  the  holes  show  up 
true,  the  amount  left  for  finishing  should  be  reduced  and, 
on  the  other  hand,  if  the  holes  fail  to  "grind  out "  the  allow- 
ance must  be  increased.  It  is  best  when  first  installing  a 
grinder  for  this  work  to  start  with  a  liberal  allowance  which 
can  be  reduced  if  too  much  stock  has  been  left. 

Cylinder  grinding  is  a  precision  operation  in  every  sense 
of  the  word,  especially  when  finishing  cylinders  for  aircraft 
engines.  For  this  reason,  the  wheel  must  be  kept  true  and 
in  cutting  condition  at  all  times.  By  again  referring  to 
Fig.  124,  it  is  seen  that  there  is  a  bracket  set  at  an  angle 
under  each  cylinder  location.  These  are  for  holding  a  dia- 

258 


INTERNAL  GRINDING 

mond  tool  used  for  truing  the  wheel.  In  this  illustration, 
the  diamond  tool  is  fastened  in  the  bracket  at  the  right  of 
the  cylinder  being  ground. 

For  grinding  cast-iron  cylinders,  carbide  of  silicon  wheels 
should  be  used.  The  grits  commonly  furnished  run  from 
30  to  36  and  the  grades  from  2  to  4  on  the  writer's  proposed 
grade  scale.  For  grinding  steel  cylinders,  alumina  abrasives 


Fig.  125. — Grinding  Hall-Scott  airplane  engine  cylinders  on  a  Heald 
cylinder  grinding  machine. 

should  be  used.  The  grits  in  this  case  run  from  30  to  40 
and  the  grades  from  i  to  4. 

Two  important  factors  involved  in  cylinder  grinding  are: 
keeping  the  work  cool  and  carrying  away  the  dust.  It  is 
needless  to  say  that  the  work  must  be  kept  cool  if  accurate 
sizes  are  to  be  maintained  while  the  dust  must  be  disposed 
of  to  conform  with  the  laws  relative  to  grinding-room  prac- 
•tice  in  force  in  the  majority  of  states. 

Excellent  means  to  attain  both  these  ends  are  illustrated 
259 


ABRASIVES  AND  ABRASIVE  WHEELS 

in  Fig.  125  which  shows  the  operation  of  grinding  cylinders 
for  the  well-known  Hall-Scott  airplane  engines.  The  cylinder 
to  be  ground  is  held  on  a  special  angle-iron  fixture  which  is 
clamped  to  the  platen  of  the  machine.  Water  supplied 
from  the  city  mains  is  circulated  through  the  water  jacket 


Fig.  126. — Grinding  a  special  internal  combustion  engine  cylinder  on  a 
Heald  cylinder  grinding  machine. 

by  means  of  the  connections  seen  at  the  top  near  the  upright 
of  the  angle  iron  and  at  the  end  of  the  cylinder.  The  dust 
is  exhausted  by  means  of  an  air  suction  connected  to  the 
exhaust  opening  of  the  cylinder. 

Cylinders  are  often  ground,  however,  with  no  provision 
made  fqr  water  cooling,  and,  if  the  depth  of  cut  taken  is 
not  too  heavy,  good  results  are  obtained.  Such  a  grinding 
operation  is  shown  in  Fig.  126.  The  work  consists  of 
grinding  a  special  cylinder  of  the  air-cooled  type.  The  dust 
can  be  readily  disposed  of  by  placing  a  hood  connected  to 
the  exhaust  system  over  the  end  of  the  hole  being  ground. 

The  cylinder  grinder  has,  without  a  doubt,  gone  a  long 
way  toward  perfecting  the  present-day  automobile  and  air- 
plane engine.  Ground  holes  are  more  accurate  than  it  is  pos- 

260 


INTERNAL  GRINDING 


sible  to  produce  by  boring  and  reaming  and  every  hole  can 
be  made  exactly  the  same  size  with  very  little  trouble. 
Far  less  accuracy  is  required  in  boring,  in  fact,  the  boring 


Fig.  127. — Grinding  the  hole  in  a  coil  spring  on  a  Heald  cylinder 
grinding  machine. 

operation  is  for  roughing  out  only  and  the  time  spent  in 
reaming  is  eliminated.  Multiple  cylinders  are  handled  as 
easily  as  are  single  ones  and  interchangeability  of  cylinders, 
pistons  and  rings  is  assured.  No  time  has  to  be  spent  in 


Fig.  128. — Grinding  a  hole  in  a  piece  of  tile  pipe  on  a  Heald  cylinder 
grinding  machine. 

lapping  a  ground  cylinder  and  a  maximum  amount  of  com- 
pression is  always  possible. 

Aside  from  cylinder  grinding,  the  cylinder  grinder  lends 
261 


ABRASIVES  AND  ABRASIVE  WHEELS 


itself  readily  to  a  number  of  operations  that  would  be  diffi- 
cult to  handle  by  ordinary  methods.  A  novel  grinding 
operation  of  this  kind  is  shown  in  Fig.  127.  This  shows  a 
flat,  coiled  spring  14  inches  in  diameter  and  10  inches  in 
length.  It  was  ground  to  a  plus-and-minus  dimension  of 
o.ooi  inches.  Another  unusual  job  is  shown  in  Fig.  128. 


Fig.  129. — Grinding  a  hole  in  a  large  worm  gear  on  a  Heald  cylinder 
grinding  machine. 

This  is  a  piece  of  tile  pipe  16  inches  long  and  8  inches  inside 
diameter  and  was  ground  to  within  a  limit  of  o.ooi  inches, 
plus-or-minus.  Fig.  129  shows  a  large  worm  gear  mounted 
for  internal  grinding.  The  manner  in  which  the  work  is 
held  in  eacli  case  is  easily  understood  by  referring  to  the 
illustrations  and  it  is  seen  that  these  pieces  did  not  require 
elaborate  special  fixtures  for  holding  them  in  position. 


CHAPTER  NINETEEN 

SPECIAL   GRINDING   OPERATIONS 

Grinding  calender  rolls — Special  grinding  machines — Roll  grinders  and  roll 
grinding — Corrugating  flour-mill  rolls — Grinding  crankshafts — Grinding 
cam  shafts — Locomotive  valve  gears. 

IN  this  category  can  be  included  a  number  of  grinding 
operations  that  are  interesting  because  of  the  ingenuity 
shown  in  adapting  the  grinding  wheel  to  unusual  problems. 
They  are  also  very  important  operations.  One  unusual 
grinding  operation  consists  of  finishing  the  calender  rolls 
of  Fourdrinier  paper-making  machines.  The  machine  takes 
its  name  from  Henry  Fourdrinier  who  introduced-  the  first 
paper-making  machine  into  England.  After  the  paper  has 
been  formed  and  partially  dried,  it  passes  through  a  series 
of  calender  rolls  which  impart  a  smooth  finish.  If  paper  were 
not  calendered,  it  would  have  the  appearance  of  a  sheet  of 
newspaper  that  had  been  wet  and  afterward  dried.  The 
largest  stack  of  calender  rolls  in  use  at  the  present  time 
in  the  United  States  or  Canada  is  shown  in  Fig.  130.  The 
relative  size  of  the  stack  can  be  judged  by  the  man  standing 
at  the  left.  When  it  is  taken  into  consideration  that  these 
rolls  are  made  of  hard  chilled  iron  and  that  they  must  have  a 
mirror-like  finish,  to  say  nothing  of  fitting  together  so  per- 
fectly that  light  will  not  show  between  them,  it  is  seen  that 
roll  grinding  is  indeed  an  exacting  operation. 

These  rolls  are  in  use  at  the  Ontario  Paper  Co.,  Thorold, 
Canada,  and  are  designated  as  follows:  Bottom,  next  to 
bottom,  intermediates  and  top.  All  these  rolls  are  196 
inches  long:  The  bottom  roll  is  30  inches  in  diameter  and 
weighs  44,000  pounds.  The  next  to  bottom  roll  is  20  inches 

263 


ABRASIVES  AND  ABRASIVE  WHEELS 

in  diameter  and  weighs  18,000  pounds.  The  intermediate 
rolls  are  seven  in  number,  14  inches  in  diameter  and  weigh 
9,000  pounds  each,  while  the  top  roll  is  the  same  diameter 
and  weight  as  the  next  to  bottom  roll. 

As  the  work  of  calender  rolls  is  nothing  more  or  less  than 
to  press  paper,  it  would  appear  that  they  should  stay  in 


Fig.  130. — The  largest  stack  of  calender  rolls  on  the  American  continent. 

shape  indefinitely,  but  this  is  not  the  case.  The  constant 
rolling  action  gradually  affects  the  mirror-like  finish  and, 
again,  the  "doctors,"  which  are  thin  plates  of  specially 
tempered  steel  used  for  scraping  them,  sometimes  leave 
scratches.  What  is  termed  a  "plug"  in  paper-mill  parlance 
often  occurs.  As  the  paper  maker  says:  "A  plug  plays  the 
mischief  with  the  rolls."  It  occurs  usually  when  the  web 
of  paper  breaks  and  banks  up  and  a  large  wad'is  pulled  be- 
tween the  rolls.  When  this  happens,  one  roll  may  stop 

264 


SPECIAL  GRINDING  OPERATIONS 

revolving  while  the  next  roll  to  it  continues  to  revolve. 
Under  these  conditions,  a  flat  spot  is  sometimes  worn  on  the 
roll. 

It  will  be  seen  that  a  special  grinding  machine  is  necessary 
to  keep  the  calenders  in  condition.  The  majority  of  paper 
mills  keep  a  few  spare  rolls  in  stock  which  are  substituted 
for  worn  ones.  Most  paper  mills  also  have  a  completely 
equipped  grinding  department  which  saves  the  time  and 
expense  involved  in  cases  wrhere  rolls  are  sent  to  a  distant 
point  for  grinding. 

As  stated  in  the  introduction,  roll  finishing  was  one  of  the 
first  attempts  at  cylindrical  grinding.  The  rolls  in  use  at 
that  time,  some  50  years  ago,  were,  of  course,  much  smaller 
than  the  ones  shown  in  Fig.  130.  A  typical  old-time  stack, 
some  50  years  old,  is  still  running  near  Ansonia,  Conn., 
and  consists  of  the  following:  A  top  roll  10x50  inches 
weighing  about  1,225  pounds,  a  bottom  roll  of  the  same 
dimensions  and  weight,  and  four  five-inch  intermediate 
rolls  weighing  a  little  over  300  pounds  each. 

Since  the  original  paper  machine,  the  prototype  of  the 
present-day  Fourdrinier  machine,  was  invented  in  1798  by 
Louis  Robert  in  France,  it  follows  that  the  early  calender 
rolls  were  not  finished  by  grinding.  The  question  naturally 
arises:  "How  were  these  hard  rolls  finished  with  the  proper 
degree  of  smoothness  to  calender  paper?"  It  is  the  writer's 
opinion  that  these  old-time  rolls  were  not  chilled  rolls  but 
simply  hard,  charcoal-iron,  sand-cast  rolls.  Thus,  they 
could  be  finished  with  turning  tools,  just  as  roll  turners  in 
steel  mills  finish  the  passes  on  rolling-mill  rolls  at  the  present 
time. 

It  is  definitely  known  that  hard,  chilled-iron  rolls  were 
made  fifty  years  ago  and  that  they  were  finished  by  grind- 
ing, probab'y  with  hand-made  grinding  wheels  consisting 
of  emery  bonded  together  with  glue~or  shellac.  Who  made 
the  first  grinding  machine  for  this  purpose,  however,  is  a 
matter  of  conjecture.  The  writer  has  made  diligent  search, 
but  is  unable  to  throw  any  light  on  the  subject. 

265 


ABRASIVES  AND  ABRASIVE  WHEELS 

A  modern  roll-grinding  machine  is  shown  in  Fig.  131. 
This  machine  is  a  product  of  the  Farrel  Foundry  &  Machine 
Co.,  Ansonia,  Conn.,  who  are  the  makers  of  the  rolls  illus- 
trated in  Fig.  130.  As  the  illustration  shows,  this  machine 
differs  radically  from  machines  for  cylindrical  grinding  as 


Fig.  131. — Parrel  self-contained  calender-roll  grinding  machine. 

described  in  a  previous  chapter.  Roll  grinding  is  a  trade 
in  itself  and  its  successful  prosecution  is  possible  only  with 
machines  built  especially  for  the  purpose. 

Briefly  described,  the  roll-grinding  machine  illustrated 
consists  of  a  massive  bed  upon  which  the  carriage,  carrying 
two  wheel  heads,  traverses,  deriving  its  motion  by  means 
of  an  automatic  screw  feed.  The  motor  for  driving  the  wheels 
is  mounted  on  a  superstructure  over  the  carriage  while  the 
carriage-driving  mechanism  is  actuated  by  means  of  the 
motor  seen  at  the  right.  This  motor  also  imparts  the  rotary 
motion  to  the  roll. 

Two  grinding  wheels,  one  on  either  side,  work  on  the  roll 
simultaneously.  This  is  for  the  object  of  expediting  pro- 
duction and  insuring  a  straight,  true  roll  at  the  same  time. 

266 


SPECIAL  GRINDING  OPERATIONS 

The  latter  feature  is  assured  by  the  swing-rest  principle 
employed  in  mounting  the  grinding  wheels.  This  principle 
has  been  in  use  for  a  number  of  years.  On  this  plan,  the 
grinding  wheels,  instead  of  being  mounted  rigidly  like  a 
lathe  tool  in  a  tool  post,  and  each  wheel  independent  of  the 
other,  are  hung  or  suspended  from  "A"  frames  on  the  wheel 
carriage  and  the  wheel  heads  are  connected  by  a  cross  bar. 
One  moves  with  the  other.  The  "A"  frames  and  the  links 
on  which  the  wheel  carriages  are  suspended  are  plainly 
shown  in  the  illustrat'on.  The  swing-rest  mechanism  is: 
supported  on  knife  edges  of  tool  steel  bearing  in  links 
which,  in  turn,  are  supported  on  knife  edges  on  a  connecting 
cross  bar.  This  allows  free  lateral  movement  and  it  insures 
a  straight  roll  because  the  straight  path  in  which  the  wheels 
are  bound  to  travel  is  not  influenced  by  any  slight  irregu- 
larities in  the  machine  bed.  To  use  a  simple  illustration, 
the  wheels  pass  along  the  rolls  just  as  a  mechanic  passes  a 
pair  of  calipers  along  a  piece  of  shafting  or  other  cylindrical 
piece  of  work. 

When  a  grinding  wheel  is  in  a  fixed  position,  as  the  tool 
in  a  lathe,  it  follows  that  any  slight  error  in  the  alignment 
of  the  ways  will  be  duplicated  on  the  face  of  the  roll.  On 
the  other  hand,  the  grinding  wheels  on  the  swing-rest  prin- 
ciple hang  like  a  plummet  and  maintain  their  relative  posi- 
tion to  each  other  on  account  of  the  cross  bar  that  con- 
nects them.  Thus,  they  traverse  in  a  straight  line,  and,, 
consequently  produce  straight  work. 

Another  important  factor  peculiar  to  roll  grinding  is  that 
comparatively  long  rolls  are  bound  to  sag  of  their  own  weight.. 


Fig.  132. — Calender  roll  sagged  through  its  own  weight.     This  illustration  is 
exaggerated  to  illustrate  the  principle. 

This  is  shown  in  Fig.  132  which  is  exaggerated  to  illustrate 
the  principle.     It  is  necessary  to  overcome  this  on  bottom 

267 


•  ABRASIVES  AND  ABRASIVE  WHEELS 

rolls,  otherwise  the  next  to  bottom  roll  would  not  make 
contact  without  sagging  and  so  on  up  the  stack.  The 
difficulty  is  successfully  overcome  by  crowning  the  bottom 
.roll  so  that  in  its  deflected  state  its  upper  surface  presents 


pig.  133. — Crowned  calender  roll.     The  crowning  compensates  the  error  due 

to  the  roll's  deflection.     This  illustration  is  exaggerated  to  illustrate 

the  principle. 

a  straight  line.  This  is  illustrated  in  Fig.  133.  This  illus- 
tration is  also  somewhat  exaggerated  to  illustrate  the 
principle. 

The  mechanism  for  crowning  is  simple  and  easily  under- 
stood. On  one  side  of  the  roll  grinder  bed,  extending  nearly 
its  whole  length,  is  an  arched  plate  called  a  master  crown 
plate.  This  is  not  shown  in  Fig.  131  as  it  is  on  the  other 
side  of  the  machine.  A  toe  piece  on  the  wheel  carriage 
travels  over  this  master  plate  and,  through  the  medium  of 
levers,  the  wheel  heads  are  moved  away  from  the  roll  as 
the  center  is  approached  and  toward  the  rol'  as  the  other 
end  is  approached.  This  imparts  the  desired  crown.  The 
mechanism  is  adjustable  to  impart  the  amount  of  crown 
necessary  for  different  lengths  and  weights  of  rolls.  It  is 
obvious  that  a  long,  comparatively  thin  roll  will  deflect 
,  more  than  a  roll  of  the  same  length,  but  of  greater  diameter, 
thus  this  adjustment  is  necessary.  The  amount  of  crown 
to  give  a  roll  to  offset  the  error  caused  by  sagging  is  de- 
termined by  experiment  alone.  To  the  best  of  the  writer's 
knowledge,  no  tables  giving  the  amount  of  crown  for  differ- 
ent lengths  and  diameters  of  rolls  have  been  published. 

Some  years  ago,  when  the  roll  grinder  had  to  depend  on 
natural  abrasives,  roll  grinding  was  a  long  and  tedious 
operation.  As  a  matter  of  fact,  weeks  were  sometimes 
consumed  in  grinding  a  single  roll  in  cases  where  it  was 
badly  out  of  shape.  The  discovery  of  Carborundum  in 
1891  proved  a  decided  boon  to  roll  grinding  as  this  abrasive 

268 


SPECIAL  GRINDING  OPERATIONS 

made  it  possible  to  accomplish  in  days  what  theretofore 
required  weeks.  At  the  present  day,  Carborundum  and 
other  carbide  of  silicon  abrasives  are  used  almost  exclusively 
for  grinding  calender  rolls. 

Shellac-bonded  wheels  are  generally  used  for  this  oper- 
ation for  two  reasons:  A  shellac-bonded  wheel  imparts 
an  *  exceedingly  fine  finish  which  is  very  desirable  and, 
again,  these  wheels  are  quite  durable.  The  grits  used  run 
from  24  to  80  in  a  medium  soft  to  soft  grade.  For  roughing 
operations,  wheels  in  vitrified  bond  are  sometimes  used. 

Roll  grinding  in  itself  is  a  comparatively  simple  oper- 
ation. The  roll  is  supported  by  its  journals  or  necks  and 
revolved  by' means  of  a  flexible  connection.  The  grinding 
should  be  worked  wet  under  all  conditions.  The  wheels 
are  fed  in  until  they  spark  heavily  and  enough  passes  taken 
over  the  roll  to  grind  it  true.  It  is  then  finished  by  means  of 
light  cuts,  the  wheels  being  allowed  to  traverse  until  no 
sparks  are  visible. 

It  is  evident  that  a  calender  roll  with  imperfections  on 
its  surface  will  not  finish  paper  satisfactorily  and,  for  this 
reason,  great  care  must  be  exercised  in  grinding  and  the 
least  tendency  to  chattering  promptly  overcome.  Chatter- 
ing, in  this  case,  is  caused  by  one  of  three  things  or  a  com- 
bination of  all  three:  Loose  wheel  spindle  boxes,  excessive 
work  speed  or  hard  wheels.  When  chattering  occurs,  the 
first  thing  to  do  is  to  see  that  the  work  speed  is  normal  and 
then  the  wheel  spindle  boxes  should  be  adjusted.  If  these 
adjustments  do  not  overcome  the  difficulty,  the  wheel  speed 
should  be  reduced  slightly,  and  if  the  wheels  are  too  hard 
the  reduction  of  speed  will  tend  to  make  them  function  as 
softer  wheels. 

The  correct  wheel-surface  speed  for  roll  grinding  is  5,000 
feet  per  minute.  Regarding  the  work  speed,  however,  there 
is  no  hard  and  fast  rule.  In  visiting  paper  mills  in  all  parts 
of  the  country,  the  writer  has  observed  work  speeds  ranging 
all  the  way  from  15  to  60  feet  a  minute  and  sometimes  more, 
and  in  -each  case  the  operator  was  getting  satisfactory  re- 

269 


ABRASIVES  AND  ABRASIVE  WHEELS 

suits.  Local  conditions  such  as  the  grade  and  make  of 
wheel  used,  the  hardness  of  the  roll,  etc.,  have  to  be  taken 
into  consideration  in  determining  the  work  speed.  Roll 
grinding,  in  the  strictest  sense  of  the  word,  is  not  a  produc- 
tion operation,  thus  the  operator  sets  the  work  speed  to 
suit  himself  and  as  long  as  he  is  getting  a  satisfactory  finish 
he  is  riot  concerned  whether  the  time  taken  to  finish  a 
certain  roll  is  three  days  or  a  week. 

Another  important  branch  of  chilled-iron  grinding  con- 
sists of  finishing  the  massive  rolls  used  in  steel  mills  for 
rolling  sheets  and  plates.  This  is  exacting  work  as  the  faces 
of  the  rolls  should  be  parallel  in  order  that  stock  of  uniform 
thickness  can  be  rolled.  Until  a  few  years  ago,  these  rolls 
were  finished  by  the  slower  process  of  turning  on  a  regular 
roll-turning  lathe.  The  manufacturers  of  cylindrical  grind- 
ing machinery,  however,  realizing  that  the  steel  mills  offered 
a  new  field  for  the  sale  of  grinding  machinery,  began  a 
series  of  exhaustive  experiments  which  ultimately  resulted 
in  the  production  of  extra-heavy,  specially  designed  ma- 
chines for  finishing  these  rolls. 

The  rolls  in  question  are  of  various  sizes  ranging  all  the 
way  from  those  used  for  rolling  ribbon  stock,  which  are 
from  8  to  12  inches  long  and  from  6  to  10  inches  in  diameter, 
up  to  the  massive  rolls  used  for  rolling  heavy  plates  which 
are  often  54  inches  in  diameter  and  15  feet  long.  The  small 
rolls  can  be  readily  ground  in  a  regular  cylindrical  grinding 
machine  and  the  process  does  not  differ  materially  from  any 
other  cylindrical  grinding  job  except,  perhaps,  that  the  wheel 
used  is  a  trifle  softer  inasmuch  as  the  amount  of  contact 
between  the  roll  and  the  wheel  prohibits  the  use  of  a  hard 
or  even  of  a  medium  grade  wheel. 

A  massive  grinding  machine  constructed  especially  for 
finishing  steel-mill  rolls  is  illustrated  in  Fig.  134.  This 
machine  is  a  product  of  the  Landis  Tool  Co.  and  in  general 
design  it  does  not  differ  materially  from  a  regular  Landis 
plain  grinder.  As  the  illustration  shows,  the  roll  is  located 
by  its  necks  or  journals  and  is  driven  from  the  face  plate 

270 


SPECIAL  GRINDING  OPERATIONS 


by  a  pin  that  engages  the  wobbler.  The  operator  stands 
on  the  three-step  platform  plainly  seen  at  the  front  of  the 
machine,  from  which  vantage  point  he  has  full  control  of 


Fig.  134. — Landis  grinding  machine  for  finishing  large  steel- mill  rolls. 

the  work  at  all  times.  He  can  look  over  the  roll  to  observe 
the  cutting  action  of  the  wheel  without  inconvenience. 
This  machine  is  self-contained  and  electrically  driven. 

Another  heavy  roll  grinding  machine  is  illustrated  in  Fig. 
135.  This  machine  is  made  by  the  Norton  Grinding  Co. 
and  is  somewhat'  more  complicated  than  the  first  machine 
shown.  In  designing  this  machine,  the  principle  of  having 
the  wheel  traverse  past  the  work  is  employed,  which  is  a 


Fig.  135. — Norton  grinding  machine  for  finishing  large  steel-mill  rolls. 

distinct  departure  from  the  Norton  Company's  practice. 

However,  in  grinding  these  massive  rolls,  it  is  readily  seen 

that  it  is  not  practicable  to  mount  the  roll  on  a  traversing 

platen.     If  this  were  done,  the  momentum  of  the  massive 

moving  body  would  present  serious  difficulties  in  reversing. 

The  wheel  is  mounted  on  a  carriage  on  which  the  operator 

271 


ABRASIVES  AND  ABRASIVE  WHEELS 

stands.  This  position  allows  him  to  view  the  grinding  oper- 
ation at  all  times.  The  roll  is  mounted  on  its  journals  and 
revolved  from  the  headstock.  The  wheel  is  fed  toward  the 
work  by  means  of  the  upper  handwheel  shown  in  the  illus- 
tration. The  machine  is  motor-driven  throughout.  The 
equipment  consists  of  five  motors  as  follows:  A  40-horse- 
power  unit  mounted  on  the  wheel  carriage  for  rotating  the 
grinding  wheel  and  traversing  the  wheel  carriage ;  a  1 5 -horse 
power  motor  mounted  on  the  headstock  for  revolving  the 
work  and  three  2 -horsepower  motors.  These  small  motors 
are  placed  on  the  head  and  tail  stocks  and  on  the  wheel 
carriage.  The  first  two  are  for  traversing  the  parts  upon 
which  they  are  mounted  along  the  ways  of  the  base,  while 
the  last  drives  the  pump  and  traverses  the  grinding  wheel 
at  right  angles  to  the  work.  This  machine  is  said  to  be  the 
heaviest  grinding  machine  ever  constructed.  It  weighs 
100,000  pounds.  After  the  first  machine  of  this  type  was 
finished  and  installed  in  a  steel  mill  for  demonstration,  it 
was  found,  after  exhaustive  trials,  that  it  reduced  the  time 
required  in  dressing  rolls  from  50  to  75  per  cent. 

There  always  has,  and  probably  always  will  be,  •  con- 
troversy regarding  the  manner  in  which  rolls  should  be 
located  for  grinding;  that  is,  by  their  centers  or  by  their 
necks.  No  matter  which  method  is  used,  the  locating  points 
must  be  true.  If  the  roll  is  to  be  located  on  centers,  these 
must  be  true  6o-degree  centers;  perfectly  round  at  all 
points,  and  free  from  scores  or  imperfections.  If  the  roll 
is  to  be  located  by  its  necks,  it  follows  that  these  must  be 
straight,  true  as  regards  circumference  and  in  line  with 
each  other.  If  the  necks  are  out  of  round,  as  they  often 
are  from  wear,  it  follows  that  the  imperfections  will  be 
duplicated  on  the  face  of  the  roll.  It  is  a  fact  that  the 
necks  of  these  massive  rolls  are  often  out  of  true  as  they 
wear  readily  due  to  the  excessive  pressure  to  which  they 
are  subjected  in  actual  use. 

A  good  method,  followed  by  many  roll  grinders,  is  first 
to  true  out  the  centers  carefully;  then  mount  the  roll  and 

272 


SPECIAL  GRINDING  OPERATIONS 

grind  the  necks  until  they  are  round  and  straight.  Then  the 
roll  is  located  by  the  necks  and  its  body  ground.  On  the 
other  hand,  many  expert  roll  grinders  have  achieved  excel- 
lent results  by  grinding  rolls  as  large  as  30  inches  in  diameter 
and  1 20  inches  long  by  locating  them  on  centers. 

The  surface  speed  of  the  wheels  used  for  roll  grinding  is 
from  5,000  to  6,000  feet  per  minute.  The  surface  speed  of 
the  work  is  comparatively  high  when  compared  to  work 
speeds  used  in  ordinary  cylindrical  grinding.  In  fact,  it 
ranges  from  100  to  200  feet  per  minute.  The  traverse 
feed  is  very  nearly  the  width  of  the  wheel  for  each  revolu- 
tion of  the  work.  The  depth  of  cut  for  roughing  is  all  the 
wheel  will  stand,  while  for  finishing  the  cut  is  comparatively 
light.  It  is  obvious  that  rolls  for  rolling  hot  steel  do  not 
require  the  mirror-like  finish  called  for  on  calender  rolls. 
Steel-mill  rolls,  however,  require  a  comparatively  smooth 
finish  as  any  imperfections  would  show  up  on  the  material 
rolled. 

Steel-mill  rolls  are  made  'of  two  materials — chilled  iron 
and  steel.  For  grinding  the  iron  rolls,  carbide  of  silicon 
is  used  and  for  steel  rolls  alumina  abrasives.  The  same 
grits  and  grades  apply  to  this  work,  in  a  general  way,  as 
given  for  grinding  calender  rolls. 

Another  important  branch  of  roll  grinding  is  the  finishing 
of  chilled-iron  rolls  used  in  flour  mills.  This  applies  to  the 
smooth  rolls  as  well  as  the  corrugated  breaking-down  rolls. 
The  corrugations  of  the  latter  wear  down  after  a  few  years' 
service  and  before  re-corrugating  them,  the  worn  corruga- 
tions .are  ground  away.  This  work  is  done  on  the  same  type 
of  machine  illustrated  in  Fig.  131.  As  flour-mill  rolls  are 
comparatively  small,  ranging  from  6  inches  in  diameter  and 
12  inches  long  to  12  inches  in  diameter  and  60  inches  long, 
a  much  smaller  machine  is  used.  These  machines  are  gen- 
erally provided  with  a  swing  rest  for  assuring  straight  rolls, 
but  they  are  seldom  equipped  with  a  crowning  attachment 
as  the  rolls  are  not  long  enough  for  their  diameter  to  deflect 
from  their  own  weight. 

273 


ABRASIVES  AND  ABRASIVE  WHEELS 

Large  flour  mills  have  their  own  grinding  and  corrugating 
departments  in  charge  of  an  experienced  operator,  but  many 
of  the  smaller  mills  send  their  rolls  to  repair  shops  that  make 
a  specialty  of  this  work.  There  seems  to  be  no  good  reason 
why  this  grinding  could  not  be  done  on  a  regular  cylindrical 
grinder  after  the  method  employed  in  grinding  small  stee"- 
mill  rolls,  but  the  type  of  grinder  shown  in  Fig.  131  seems  to 
have  the  preference. 

In  grinding  the  worn  corrugations  from  flour-mill  rolls, 
carbide  of  silicon  whee  s  in  30  to  60  grit  and  medium  grade 
are  used.  Shellac-bonded  wheels  are  always  used  for  finish- 
ing operations,  but  for  roughing  some  operators  prefer 
vitrified  whee's.  The  work  does  not  differ  materially  rom 
any  other  roll-grinding  operation  and  the  process  followed 
is  the  same. 

After  the  automobile  had  passed  the' experimental  stage 
and  began  to  be  an  industry  in  tself,  one  of  the  complex 
problems  it  brought  about  was  the  finishing  of  crankshafts. 
It  goes  without  saying  that  tne  bear  ngs  and  pins  of  this 
important  member  of  the  modern  automobile  must  be  ac- 
curately and  smoothly  finished  if  an  easy-running  motor 
is  to  result  and,  as  may  be  imagined,  abrasive  engineers 
lost  no  time  in  adapting  the  cylindrical  grinder  for  finishing 
crankshafts.  In  the  early  days  of  the  automobile  industry, 
the  grinding  of  crankshafts  presented  many  difficulties. 


Fig.  136^ — Typical  crankshaft  as  finished  by  grinding. 

The  shaft  was  usually  held  between  centers  on  offset  blocks. 
This  method  when  applied  to  a  four  or  six  throw  crankshaft 

2/4 


SPECIAL  GRINDING  OPERATIONS 

is  not  satisfactory  as  the  shaft  is  quite  liable  to  spring  in 
the  grinding  operation,  owing  to  the  insecure  support. 
Again,  in  the  early  days  of  four- throw  crankshafts,  there 
were  no  grinding  wheels  suitable  for  the  work,  that  is,  as 
we  judge  such  wheels  today. 

A  typical  crankshaft,  one  that  is  easily  finished  by  grind- 
ing, is  shown  in  Fig.  136.  This  is  an  easy  shaft  to  grind 
as  it  has  but  one  intermediate  bearing  and  four  pin  bearings. 


Fig.  137. — Landis  crankshaft  grinding  machine. 

A  modern  Landis  crankshaft  grinder  is  illustrated  in  Fig. 
137.  This  machine  does  not  differ  materially  from  an 
ordinary  cylindrical  grinder  with  the  exception  that  the 
crankshaft  is  rotated  and  driven  from  both  ends  while  it 
is  securely  held  in  special  indexing  devices  which  are  counter- 
weighted  to  assure  a  satisfactory  running  balance  to  the 
shaft  during  the  grinding  operation.  The  double  drive  is 
derived  from  the  shaft  seen  at  the  front  of  the  machine. 

The  work-carrying  fixture  is  shown  in  Fig.  138.  These 
are  attached  to  the  face  plates  of  the  machine  and  carry 
the  work  while  grinding  the  pins.  The  fixtures  are  equipped 
with  two  independent  rotary  adjustments,  one  an  eccentric 
for  obtaining  different  throws,  the  settings  for  which  are 

275 


ABRASIVES  AND  ABRASIVE  WHEELS 


Fig.  138.— Work-carrying  fixture  for  grinding  crankshafts  on  Landis 
-       crankshaft  grinding  machine. 


Fig.  139. — Special  wheel-truing  device  for  Landis  crankshaft  grinding  machine. 

276 


SPECIAL  GRINDING  OPERATIONS 

indicated  in  English  and  Metric  scales,  and  the  other  for 
locating  the  pins  in  their  relative  grinding  positions.  The 
setting  for  this  is  controlled  by  a  division  index  which  is 
of  the  tapered  type  to  insure  it  against  reasonable  wear. 
The  counterbalance  weights  are  seen  at  the  bottom  of  the 
face  plate. 

Another  attachment  peculiar  to  crank-grinding  machines 
is  the  special  radius  truing  device  which  is  absolutely  nec- 
essary in  keeping  the  corners  of  the  wheel  at  the  correct 
radius  to  impart  the  desired  fillets  on  the  work.  A  Landis 
special  wheel-truing  device  of  this  type  is  illustrated  in 
Fig.  139.  This  is  attached  to  the  top  of  one  of  the  work- 
rests  used  in  supporting  the  crank  while  grinding.  The 
diamond  tool  is  oscillated  by  the  lever  at  the  top.  This 
fixture  is  also  used  for  truing  the  face  of  the  wheel  and, 
as  the  illustration  shows,  the  work  need  not  be  removed 
when  the  device  is  in  use.  As  shown,  the  diamond-setting 
gauge  is  turned  over  and  pushed  back  on  its  holder  where  it 
does  not  interfere  with  the  truing  operation. 

Crankshafts  are  finished  in  two  ways,  grinding  from  the 
rough  forging  and  finish  grinding  after  a  roughing  cut  in 
the  lathe.  There  is  some  controversy  as  to  which  is  the 
best  method,  but  in  actual  practice  both  methods  give  ex- 
cellent results.  In  grinding  a  crankshaft  from  the  rough, 
it  is  first  centered  and  the  main  bearings  roughed  out.  Then 
it  is  held  in  the  offset  fixtures  and  the  pins  roughed  out. 
Next  the  pins  are  finished  carefully  and  last  of  all  the  main 
bearings. 

In  the  other  process,  the  roughing  is  done  in  the  lathe 
and  the  grinding  machine  used  for  the  finishing  operation 
only.  In  this  case,  the  main  bearings  are  first  rough  ground 
to  within  a  few  thousandths  of  the  finished  size,  then  the 
pins  are  roughed.  Next  the  pins  are  finished  and  last  of  all 
a  finishing  cut  is  taken  over  the  main  bearings. 

Grinding  from  the  rough  wears  out  wheels  rapidly,  but 
as  the  turning  operation  in  the  lathe  is  eliminated,  there 
may  be  truth  in  the  claim  that  this  method  is  the  most' 

277 


ABRASIVES  AND  ABRASIVE  WHEELS 

rapid.  However,  many  leading  manufacturers  prefer  to 
take  the  roughing  cuts  in  the  lathe.  Thus,  it  is  seen  that 
there  must  be  factors  in  favor  of  both  methods,  otherwise 
one  or  the  other  would  be  adopted  universally. 

Crank  grinding  is  an  exacting  operation  and  the  speed 
with  which  the  work  is  turned  out  is  attained  only  by  long 
practice  on  the  part  of  the  operator.  It  differs  from  ordinary 
grinding  in  several  ways.  In  the  first  place,  in  working  on 
the  pins,  the  traverse  feed  is  eliminated  entirely  and  the 
work  fed  directly  to  the  wheel  by  means  of  the  cross  feed. 
The  face  of  the  wheel  must  be  kept  true  and  straight  in  the 
finishing  operation.  Again,  the  operator  has  to  exercise 
care  in  watching  the  fillets,  for  a  true  radius  on  the  wheel 
corner  is  necessary  in  imparting  the  desired  fillet  on  the 
finished  work.  Another  point  that  requires  close  attention 
on  the  part  of  the  operator  is  the  spacing  of  the  pins.  Crank- 
shaft grinding  is  a  special  trade  in  itself  and  in  common 
with  other  exacting  operations,  skill  is  developed  only 
through  long  practice. 

As  crankshafts  are  always  made  of  steel,  alumina  abrasives 
are  used  for  grinding  them.  Grinding-wheel  manufacturers 
who  cater  to  this  class  of  trade  have  developed  special 
wheels  for  the  work.  These  wheels  are  generally  in  com- 
bination grits  and  great  care  has  been  paid  to  developing 
bonds  that  will  insure  the  corners  holding  up  well  with- 
out danger  of  burning  the  work.  The  wheels  used  for 
grinding  crankshafts  from  the  rough  are  coarse  and  com- 
paratively hard — from  16  to  24  grit  in  the  writer's  grades 
ii  to  14.  For  finishing,  finer  and  softer  whee's  are  used. 
The  grits  in  this  case  run  from  36  to  AO  and  the  grades 
from  7  to  9. 

Perhaps  the  greatest  difficulty  experienced  in  crankshaft 
grinding  is  keeping  the  work  true.  It  is  imperative  that 
free-cutting  wheels  are  used,  but  they  must  not  be  too  soft, 
otherwise  more  wheel  is  wasted  in  keeping  the  fillets  at  the 
proper  radii  than  is  used  in  actual  grinding.  If  the  wheels 
are  too  hard,  in  the  finishing  operation,  they  heat  the  metal 

278 


SPECIAL  GRINDING  OPERATIONS 

unduly  wfyich  causes  sprung  work  and  burned  spots  in  the 
fillets.  Especial  care  must  be  exercised  in  taking  the  finish- 
ing cuts  on  the  main  bearings  as  these  must  test  true,  or 
at  least  within  close  limits,  in  the  finished  shaft.  An  expert 
can,  of  course,  bend  a  sprung  shaft  until  it  runs  true,  but 
it  is  much  better  to  have  the  work  true  as  it  comes  from 
the  grinder. 

The  finish  left  on  the  journals  and  pins  is  another  im- 
portant factor  and  the  high  degree  of  finish  required  by 
the  government  on  crankshafts  for  airplane  motors  has 
caused  more  than  one  manufacturer  much  anxiety.  There 
was  a  time  when  manufacturers  of  crankshafts  used  a  final 
lapping  with  emery  cloth  and  oil  to  impart  a  high  degree  of 
finish,  but  the  government  frowns  on  this  practice. 

The  amount  to  be  left  for  finishing  should  be  determined 
by  experimentation  as  it  is  impossible  to  set  any  definite 
rule.  The  accuracy  with  which  the  shafts  are  roughed 
out,  both  as  regards  dimensions  and  the  spacing  of  the  off- 
sets are  important  factors  bearing  on  this  point.  Again, 
the  size  of  the  shaft,  whether  long  or  short  must  be  con- 
sidered. On  an  average,  however,  0.020  inch  should  suffice 
in  the  majority  of  cases  where  the  operator  who  roughs 
out  the  work  uses  reasonable  care. 

Never  under  any  conditions  should  it  be  attempted  to 
grind  a  crankshaft  without  backresting  it.  Crank  grinding 
machines  are  equipped  with  a  special  form  of  back  rest  that 
bears  directly  on  the  surface  being  ground  and  there  is  no 
excuse  for  not  using  these. 

Another  special  grinding  operation  that  has  been  de- 
veloped by  the  automobile  industry  is  that  of  grinding 
cam  shafts.  In  the  early  development  of  the  internal- 
combustion  motor,  in  the  days  of  single  cylinder  and  two 
cylinder  double-opposed  type  engines,  individual  cams  wrere 
used.  These  were  cut  by  methods  used  in  cutting  ordinary 
face  cams  after  which  they  were  hardened  to  eliminate  wear. 
These  early  cams  were  not  ground;  for  at  that  time  rule-of- 
thumb  methods  were  the  general  ones  employed,  thus  after 

279 


ABRASIVES  AND  ABRASIVE  WHEELS 

the  cams  were  hardened,  a  polishing  with  abrasive  cloth 
was  thought  sufficient. 

As  the  automobile  engine  was  gradually  improved,  the 
valve-actuating  mechanism  was  given  more  attention  and 
more  accurately  finished  cams  were  demanded.  Grinding- 
machine  manufacturers  turned  their  attention  to  the  de- 
velopment of  special  attachments  for  cam  grinding. 

Present-day  internal-combustion  engine  cams  are  of  two 
kinds:  Integral  cams,  in  which  several  cams  are  made  in- 
tegral with  their  shaft,  and  individual  cams.  The  former 
type  is  the  one  most  extensively  used.  The  latter  type  is 
sometimes  used  on  multiple  cylinder  engines,  in  which  case 
the  cams  are  pinned  or  otherwise  fastened  permanently 
to  the  shaft.  The  majority  of  individual  cams,  however, 
are  used  on  single  cylinder  engines  of  various  types. 

There  are  two  types  of  cam-grinding  attachments  to  take 
care  of  the  two  kinds  of  cams  above  referred  to.  An  attach- 
ment made  by  the  Norton  Grinding  Co.  for  finishing  in- 
dividual cams  is  shown  in  Fig.  140.  Briefly  described,  it 
consists  of  a  spindle  which  carries  the  cam  to  be  ground 
and  the  master  cam  which,  running  over  a  roller,  produces 
the  desired  contour  of  the  cam  face.  It  is  driven  from  the 
headstock  of  the .  machine  and  a  strong  spring  keeps  the 
master  cam  in  contact  with  its  roller  while  the  cam  is  brought 
to  the  Wheel  by  means  of  the  cross  feed. 

An  attachment  designed  for  grinding  integral  cams  is  shown 
in  Fig.  141,  while  Fig.  142  is  a  close-up  view  of  the  attach- 
ment taken  from  the  back  of  the  machine.  The  gear  guards 
are  removed  in  this  view  to  show  the  operating  mechanism. 
A  is  the  driving  arm,  B  the  master  cams  on  their  spindle, 
C  the  roll  which  is  set  in  position  before  the  desired  leader 
by  slipping  along  the  shaft  D.  This  is  equipped  with  a 
locking  device  to  hold  it  in  place  as  occasion  requires. 
E  is  the  case  that  covers  a  stiff  spring  which  holds  the  master 
cam  in  contact  with  the  roll.  F  is  the  driving  dog,  G  the 
steady-rests  and  H  the  tailstock.  As  the  master  cams  are 
revolved  their  bearing  against  the  roll  causes  the  attach- 

280 


SPECIAL  GRINDING  OPERATIONS 


Fig.  140. — Norton  grinding  attachment  for  finishing  individual  cams. 


Fig.  141. — Norton  grinding  attachment  for  finishing  cams  made  integral  with 
their  shafts. 


281 


ABRASIVES  AND  ABRASIVE  WHEELS 

ment  to  oscillate  which,  of  course,  produces  a  duplicate 
motion  of  the  cams  in  position  before  the  grinding  wheel. 

In  cam  grinding,  no  traverse  feed  is  used.  The  wheel  is 
fed  directly  into  the  work  by  means  of  the  cross  feed  until 
the  required  depth  is  reached.  The  handle  J  is  for  the  pur- 


Fig.  142. — Rear  view  of  Norton  cam-grinding  attachment. 

pose  of  lifting  the  work"  away  from  the  wheel  for  inspection 
and  removal  and  to  move  the  guide  roll  from  one  position  to 
another. 

In  cam-grinding,  it  is  very  necessary  to  use  steady-rests 
to  support  the  work.  These  should  be  located  reasonably 
close  to  the  cam  being  ground  and  should  bear  on  the  round 
part  of  the  shaft  which  is  finished  by  grinding  for  this  pur- 
pose. The  Norton  Grinding  Co.  provide  two  types  of 
steady-rests,  as  illustrated  in  Figs.  143  and  144.  Fig.  143 
is  an  open  type  rest  and  Fig.  144  a  closed  type  rest.  It  is 
obvious  that  the  open  type  has  the  advantage  of  being 
readily  handled  in  locating  and  removing  the  work.  The 
closed  rest  is  used  in  cases  where  great  accuracy  is  demanded, 
for  instance,  on  cams  for  high-class  automobile  engines  and 
on  aircraft  engine  work. 

282 


SPECIAL  GRINDING  OPERATIONS 

As  the  cams  in  question  are  made  of  steel,  alumina  abra- 
sives are  used  in  grinding  them.  The  degree  of  accuracy 
demanded  and  the  finish  sought  are  important  factors 
governing  the  selection  of  wheels  for  cam  grinding.  For 


Fig.    1 43 .  —  Open  -  type    Norton 
steady-rest  for  camshaft  grinding. 


Fig.  144.  —  Closed -type  Norton 
steady-rest  for  camshaft  grinding. 


roughing  out  the  cams  before  they  are  hardened,  which  is 
common  practice,  wheels  in  16  to  24  grit  and  12  to  17  grades 
will  be  found  satisfactory.  It  is  seen  here  that  the  wheels 
used  for  this  purpose  are  comparatively  hard.  For  roughing 
out  hardened  cams  24  to  40  grit  in  grades  4  to  7  will  give 
good  results.  For  finishing  hardened  cams,  grits  36  to  50 
in  grades  3  to  5  will  be  found  satisfactory.  The  grades  are 
according  to  the  writer's  grade  scale. 

One  of  the  most  interesting  factors  pertaining  to  cam 
grinding  is  the  method  followed  in  producing  the  leaders 
or  master  cams.  It  is  necessary  that  these  be  accurate  as 
regards  contour  if  accurate  results  in  the  ground  cams  are 
sought.  In  grinding  a  cam,  we  use  a  leader  of  the  desired 
form  to  produce  the  outline  on  the  cam  that  oscillates  be- 
fore the  grinding  wheel.  In  making  these  leaders,  we  re- 
verse the  practice.  This  will  be  clearly  understood  by  the 
following  description.  The  operation  is  shown  in  Fig.  145. 
This  is  the  same  attachment  used  for  cam  grinding  but  set 
up  differently.  In  place  of  the  grinding  wheel  the  disk  (2) 
is  used.  This  is  made  of  cast  iron  and  occupies  the  position 

283 


ABRASIVES  AND  ABRASIVE  WHEELS 

taken  by  the  grinding  wheel  in  grinding  operations.  The 
model  cam  (4)  bears  against  the  disk  and  from  it  is  produced 
the  leader,  several  of  which  are  shown  at  5.  This  is  ground 
by  the  grinding  wheel  (i).  The  spindle  (6)  carries  the  master 


Fig.  145. — Grinding  the  leaders  for  a  Norton  cam-grinding  attachment. 

cams.  The  master  cams,  which  are  hardened,  were  roughed 
approximately  to  the  desired  shape  before  hardening.  The 
bearings  of  the  master-cam  spindle  and  the  centers  of  the 
attachment  must  be  exactly  in  line.  As  the  grinding  wheel 
and  the  master  cam  revolve,  the  model  runs  over  the  disk 
which  produced  the  desired  contour  on  the  master.  It 
looks  simple,  which  in  truth  it  is,  but  to  assure  satisfactory 
results  two  .important  factors  must  be  borne  in  mind.  The 
disk  (2)  must  be  the  size  of  the  grinding  wheel  that  is  to  be 
used  in  grinding  the  cam  on  regular  production  work  and 
the  grinding  wheel  (i)  must  be  exactly  the  same  size  as 
the  roll  that  is  to  follow  over  the  master  cams  when  they 
are  in  use  as  producers  for  the  finished  cams. 

As  previously  stated  the  master  cams  are  roughe'd  out 
before  they  are  hardened  and  a  few  words  concerning  a 

284 


SPECIAL  GRINDING  OPERATIONS 


simple  method  to  follow  in  marking  the  outline  will  not 
be  out  of  place  here.  The  blanks,  while  soft,  are  mounted 
on  the  roughing  master-cam  spindle,  it  being  understood 
that  in  cam  grinding  two  sets  of  masters  are  necessary,  one 
for  roughing  and  the  other  for  finishing  master  cams.  The 
machine  is  started  up  and  the  model  produces  the  desired 
motion  to  the  master  cam  shaft.  The  wheel  (i)  is  brought 
to  bear  slightly  against  the  side  of  the  master  where  it 
marks  the  outline  from  which  the  toolmaker  roughs  out 
the  cam. 

As  stated  previously,  the  disk  over  which  the  model  cam 
runs  in  making  a  master  cam  must  be  the  same  size  as  the 


-Roll4"Diam. 


Pivcrt^ 


Trammel -9  "Rod.  representing 
Grinding  Wheel 


Generated  with          Generated  with  Generated  with 

Under  Sue  Wheel       Correct  Size  Wheel  Over  Size  Wh»el 

(18  Diam.) 

Fig.  146. — Effect  of  varying  wheel  diameters  in  cam  grinding. 

grinding  wheel  to  be  used  in  grinding  the  cams  later  in  pro- 
duction work.  As  all  grinding  wheels  wear  in  use,  it  is 
evident  that  after  the  wheel  is  worn  away  somewhat  it  will 
not  grind  the  same  shape  as  it  did  when  it  was  up  to  size. 
This  is  graphically  illustrated  in  Fig.  146  which  was  pre- 
pared for  explanatory  purposes  by  Howard  W.  Dunbar, 
and  illustrates  clearly  just  what  takes  place  in  cam  grinding. 
The  model  cam  is  in  position  bearing  against  the  guide  roll. 

285 


ABRASIVES  AND  ABRASIVE  WHEELS 

A  piece  of  cardboard  is  glued  to  the  master,  this  taking  the 
place  of  the  cam  to  be  ground  under  working  conditions. 
The  pencil  represents  the  periphery  of  the  grinding  wheel. 
A  mark  is  made  on  the  cardboard  with  the  pencil,  the  master 
moved  a  little  and  another  mark  made  and  so  on  until  the 
master  has  made  a  complete  revolution.  This  gives  the 
cam  outline  seen  in  the  illustration.  If  the  radius  on  which 
the  pencil  swings  is  changed  to  represent  the  periphery  of 
a  smaller  wheel,  a  different  shaped  cam  will  be  formed. 
As  the  three  diagrams  at  the  bottom  of  the  illustration 
show,  incorrect  wheel  sizes  make  a  vast  difference  in  the  out- 
line produced  even  though  the  same  master  is  used.  From 
this  it  is  seen  that  after  a  wheel  is  worn  down  a  little,  two 
courses  are  before  the  man  who  wants  to  produce  cams  true 
to  a  predetermined  contour.  Either  discard  the  wheel 
after  it  has  worn  away  a  little  and  substitute  a  new  one 
that  is  up  to  size  or  produce  a  multitude  of  leaders  from 
different -sized  disks  to  be  substituted  as  the  wheel  wears 
away.  These  masters,  it  is  needless  to  say,  should  be 
stamped  to  show  what  size  wheel  they  were  made  to  be 
used  with. 

Another  interesting  grinding  operation  consists  of  finish- 
ing the  radii  on  links  used  in  valve  gears  as  seen  on  loco- 
motives. Three  types  of  links  are  shown  in  Fig.  147.  A 
is  a  built-up  link  in  which  the  members  i  and  2,  that  con- 
fine the  block  D,  are  held  together  with  bolts,  the  intervening 
spaces  being  filled  with  the  filler  pieces  3.  Links  of  this 
type  are  generally  made  of  wrought  iron  and  protected 
against  excessive  wear  by  case  hardening.  A  solid  link 
is  shown  at  B.  Links  of  this  type  are  generally  made  from 
steel  castings.  Sometimes  they  are  case  hardened,  but  in 
other  instances  they  are  left  in  their  soft  state.  The  link 
shown  at  C  is  the  type  used  in  the  Walschaert  valve  gear. 

Considering  the  link  shown  at  A,  it  is  evident  that  case 
hardening  will  distort  it  to  a  certain  extent.  If  satisfactory 
working  surfaces  are  desired,  the  errors  must  be  corrected 
by  grinding.  Some  years  ago,  links  of  this  type  were  ground 

286 


SPECIAL  GRINDING  OPERATIONS 


by  hand  on  the  face  of  a  wide  wheel.  This  practice,  of  course, 
called  for  the  services  of  an  expert  workman  and  even 
under  these  conditions  the  results  were  not  always  satis- 
factory. 

The  machine  shown  in  Fig.  148  was  designed  especially 
for  grinding  links  and  link  blocks  and  is  called  a  radial 


Fig.  147. — Three  types  of  locomotive  valve-gear  links. 

grinder.  However,  as  these  machines  are  used  principally 
in  railroad  shops  they  are  generally  called  link  grinders. 
The  machine  is  designed  and  built  by  H.  G.  Hammett, 
Troy,  N.  Y. 

The  fulcrum  of  the  bar  seen  in  the  foreground  is  adjust- 
able to  accommodate  links  of  different  radii  and  causes 
the  upper  section  of  the  platen  to  describe  a  curve  as  it 
traverses  back  and  forth.  The  grinding  wheel  is  carried  on 
a  vertical  spindle  and  is  fed  downward  as  the  grinding  pro- 
gresses. The  link  is  lined  up  to  the  desired  radius  and 
securely  strapped  to  the  platen  of  the  machine,  although  in 
some  cases  special  fixtures  are  provided  for  locating  the  work. 

287 


ABRASIVES  AND  ABRASIVE  WHEELS 

In  fitting  up  links  of  any  kind,  the  first  step  is  generally 
to  grind  the  block  which  is  then  used  as  a  gauge  in  grinding 
the  link  to  the  correct  width.  This  is  a  much  easier  pro- 
cedure than  to  attempt  to  grind  the  link  first  and  then 


Fig.  148. — Hammett  link-grinding  machine. 

fit  the  block.  In  fitting  up  new  links  of  the  type  shown  at  A, 
the  built-up  link,  excellent  results  can  be  obtained  by  grind- 
ing the  block  and  fillers  at  one  operation  and  the  other 
members  next.  In  assembling,  the  clearance  to  allow  the 
block  to  slide  is  obtained  by  means  of  paper  shims  or  liners 
placed  between  the  fillers  and  the  members  i  and  2. 

Links  wear  quite  rapidly,  especially  those  used  in  con- 
nection with  Stephenson  link  motions.  This  is  due  prin- 
cipally to  the  slip  of  the  block  caused,  among  other  things, 
by  offsetting  the  saddle  pin  to  secure  the  desired  cut-off 
motion.  Built-up  links  can  be  readily  re-ground  and  new 
blocks  fitted,  but  with  solid  links  the  only  thing  to  do  is  to 
grind  them  until  the  radii  are  trued  up  and  then  fit  new 
blocks. 

The  operation  of  link  grinding  is  simple  after  the  link 
288 


SPECIAL  GRINDING  OPERATIONS 

has  been  correctly  located  on  the  platen  of  the  machine. 
The  depth  of  cut  should  be  comparatively  light  as  this 
work  is  done  dry  and  the  wheel  should  be  fed  down  by  means 
of  the  automatic  feed.  The  wheels  generally  used  are  from 
30  to  40  grits  in  the  writer's  12  grade.  As  the  work  is 
steel,  an  alumina  abrasive  should  be  used. 


CHAPTER  TWENTY 

CUTTER    SHARPENING 

Machines  employed  for  cutter  grinding — Adjustments  and  attachments  on 
cutter  grinders — Grinding  spiral  cutters — General  operation  of  cutter 
grinders — Selection  of  wheels — Speeds — Depth  of  cut. 

'T'O  insure  maximum  production  on  the  milling  machine, 
A  it  is  necessary  to  use  properly  sharpened  cutters.  Dull 
cutters  throw  an  extra  load  on  the  machine,  produce  un- 
satisfactory surfaces  and  leave  heavy  burrs.  Cutter  sharpen- 
ing is  a  comparatively  simple  operation  that  can  be  done 
by  any  mechanic  of  ordinary  ability,  provided  reasonable 
care  is  exercised  to  see  that  the  depth  of  cut  is  not  deep 
enough  to  cause  the  wheel  to  burn  the  teeth.  There  are 
two  kinds  of  machines  used  for  cutter  grinding,  small 
universal  grinders  arranged  for  dry  grinding  and  special 
cutter  sharpening  machines.  A  machine  of  the  former  type 
is  illustrated  in  Fig.  149.  This  is  a  product  of  the  Cin- 
cinnati Milling  Machine  Co.  and  is  the  result  of  many 
years'  study  and  experimentation  to  produce  an  economical 
machine  that  could  be  adapted  to  cutter  grinding  and  small 
tool-room  cylindrical  grinding. 

On  this  machine  the  base,  platen  and  head  are  all  equipped 
with  swivel  adjustments  while  a  vertical  adjustment  is  also 
provided  to  enable  the  machine  to  take  care  of  such  work 
as  grinding  formed  cutters  without  having  to  resort  to  the 
use  of  drop  centers.  Owing  to  its  wide  range  of  adjust- 
ments, this  machine  can  be  readily  adapted  to  any  kind  of 
cutter  grinding. 

The  machine  shown  in  Fig.  150  is  a  Brown  &  Sharpe 
290 


CUTTER   SHARPENING 

cutter  grinder.  It  embodies  a  number  of  adjustments  and, 
with  the  necessary  attachments,  can  be  set  up  to  do  any 
kind  of  cutter  grinding.  The  operation  shown  in  Fig.  150 


Fig.  149. — Cincinnati  universal  grinding  machine  adapted  for  tool-room 
and  cutter  grinding. 

is  that  of  grinding  the  peripheral   teeth  on   an   ordinary 
milling  cutter,     For  grinding  end  mills,  the  work  is  located 

291 


ABRASIVES  AND  ABRASIVE  WHEELS 

in  a  sleeve  that  fits  the  swivel  head  seen  under  the  oper- 
ator's hand.  The  attachment  shown  in  Fig.  155,  is  for 
grinding  the  end  teeth  of  cutters  and  similar  pieces  while 
the  attachment  illustrated  in  Fig.  163  is  for  grinding  formed 
cutters. 

While  the  primary  object  in  sharpening  a  milling  cutter 
is  to  put  its  teeth  in  cutting  condition,  care  must  be  exer- 


Fig.  150. — Grinding  the  peripheral  teeth  of  a  milling  cutter  on  a  Brown  & 
Sharpe  cutter  grinding  machine. 

cised  to  see  that  the  cutter  is  kept  round  and  that  the  teeth 
are  ground  straight  with  the  axis  of  the  cutter.  If  the  cutter 
is  not  round,  comparatively  few  of  its  teeth  cut  and  if  it  is 
tapered  accurate  work  cannot  be  obtained. 

One  of  the  most  rapid  and  simple  methods  of  sharpening 
a  cutter  properly,  with  the  above  factors  in  mind,  is  shown 

292 


CUTTER   SHARPENING 

in  Fig.  1 50.  The  cutter  is  mounted  on  a  hollow  work  arbor 
as  shown  in  Fig.  151  where  it  is  held  between  two  collars, 
A  and  B.  These  collars  have  several  steps  on  them  to  ac- 
commodate cutters  with  different -sized  arbor  holes.  This 
hollow  arbor  carrying  the  cutter  is  slid  back  and  forth  by 


Fig.  151. — Hollow  work  arbor  for  locating  milling  cutters  for  grinding. 

hand  along  the  bar  C,  which  is  also  seen  in  Fig.  150.  This 
bar  is  clamped  in  the  swivel  head.  If  the  bar  is  straight,  it 
naturally  follows  that  the  teeth  of  the  cutter  will  be  ground 
parallel,  regardless  of  the  setting  of  the  swivel  head,  and 
if  the  work  arbor  is  true,  a  round  cutter  will  result.  This 
method  of  cutter  grinding  is  not  new  by  any  means,  but  it 
produces  accurate  results. 

The  first  step  in  setting  up  the  cutter  grinder  is  to  clamp 
the  cutter  on  the  work  arbor,  set  the  bar  in  place  and  then 
set  the  guiding  finger  under  the  cutter  tooth  nearest  the 
wheel  to  impart  the  correct  angle  for  clearance.  This  is 
generally  from  five  to  seven  degrees.  Too  little  clearance 
will  cause  the  cutter  to  cut  slowly,  while  too  great  a  clear- 
ance makes  the  teeth  dull  quickly.  In  setting  the  guide 
finger  to  impart  the  desired  clearance,  the  expert  operator 
is  generally  guided  by  experience  alone. 

In  grinding,  the  cutter  should  be  fed  past  the  wheel  with 
a  fairly  quick  motion  and  the  depth  of  cut  should  be  com- 
paratively light  as  this  work  is  generally  done  dry  and 
thus  it  is  obvious  that  a  deep  cut  will  burn  the  tooth.  It 
is  a  good  plan  to  mark  the  first  tooth  with  chalk  and  grind 
the  teeth  evenly  and  carefully  until  all  have  been  sharpened. 
It  is  generally  found  that  the  wheel  wears  a  little  in  going 
around  the  cutter  once  and  for  this  reason  a  very  light 
finishing  cut  should  be  taken  to  insure  the  cutter  not  being 

293 


ABRASIVES  AND  ABRASIVE  WHEELS 

out  of  round  from  excessive  wheel  wear.  In  connection 
with  this  point  it  may  be  well  to  mention  the  fact  that  com- 
paratively wide-faced  wheels  give  better  results  in  cases 
where  they  can  be  used  than  do  narrow  ones,  owing  to  the 
fact  that  the  wide-faced  wheel  wears  longer. 

A  spiral  cutter  is  ground  in  the  same  manner  as  a  straight 
one  with  the  exception  that  the  guide  finger  is  set  to  con- 
form to  the  pitch  of  the  spiral.  It  is  a  more  difficult  matter 


Fig.  152. — Grinding  a  milling  cutter  with  the  guide-finger  over  the  tooth. 

to  grind  spiral  cutters  than  straight  ones  as  an  inexperienced 
operator  sometimes  has  difficulty  in  setting  the  guide  finger 
properly  and  in  keeping  the  cutter  in  correct  contact. 

There  are  two  ways  to  locate  the  guide  finger  in  grinding 
milling  cutters  and  both  have  their  good  and  bad  features. 
By  again  referring  to  Fig.  150,  it  is  seen  that  the  guide 
finger  is  under  the  tooth  being  ground.  The  wheel  is  run- 
ning toward  the  operator.  Thus  the  action  of  the  wheel 

294 


CUTTER   SHARPENING 

keeps  the  cutter  tooth  in  contact  with  the  guide  finger. 
This  is  the  safest  way  to  grind  a  milling  cutter,  but  it  is 
more  liable  to  burn  the  teeth  than  the  method  illustrated 
in  Fig.  152  In  the  latter  method,  it  is  seen  that  the  guide 
finger  is  placed  just  opposite  to  what  it  is  in  the  former  case 
and  also  that  the  cutter  has  been  reversed.  The  operator 
must  exercise  great  care  to  keep  the  cutter  in  contact  with 
the  wheel,  the  action  of  which  has  a  tendency  to  pull  the 
work  away  from  the  guide  finger.  Should  the  operator 
relax  his  diligence,  the  wheel  might  force  the  tooth  away 
from  the  guide  finger  which  would  result  in  an  injured  tooth 
or  perhaps  a  broken  wheel.  In  grinding  cutters  by  this 
method,  the  wheel  is  not  as  liable  to  burn  the  work,  thus  a 
deeper  cut  can  be  taken.  For  this  reason,  this  method  is  used 
by  many  mechanics.  In  considering  the  best  method  to  use,  it 
is  best  for  a  green  operator  to  use  the  first-described  one  while 
the  latter  should  be  left  for  more  experienced  operators. 

In  grinding  the  teeth  of  a  straight  or  spiral  milling  cutter, 
the  clearance  is  obtained  by  raising  or  lowering  the  guide 
finger.  In  grinding  angular  cutters,  however,  another 


Fig.  153. — Correct  and  incorrect  methods  of  locating  angular  cutters  for 
grinding,  j 

method  must  be  used.  Correct  and  incorrect  set-up  posi- 
tions for  angular  cutters  are  shown  in  Fig.  153.  A  illus- 
trates the  correct  position  in  which  the  tooth  makes  a 
straight  line  toward  the  center.  This  is  necessary  in  pre- 
serving the  correct  angle  as  given  by  the  swivel  head  when 

295 


ABRASIVES  AND  ABRASIVE    WHEELS 


the  machine  is  set  up  for  the  grinding  operation.  If  the 
guide  fingers  were  dropped  to  give  the  clearance  angle, 
the  result  as  shown  in  B  would  be  had.  Here  it  is  seen  that 
the  tooth  does  not  bear  evenly  on  the  guide  finger. 

In  setting  up  the  cutter  grinder  for  grinding  teeth  on 
angular  cutters,  the  clearance  is  obtained  by  raising  the 


Fig.  154. — Grinding  an  angular  milling  cutter  on  a  Cincinnati  grinder. 

wheel  center  above  that  of  the  cutter  in  the  machine  shown 
in  Fig.  154,  which  is  a  Cincinnati  grinder  set  up  for  grind- 
ing the  peripheral  teeth  of  an  angular  cutter.  The  cutter 
is  held  on  the  end  of  the  swivel  head  spindle  and  the  angle 
for  clearance  obtained  by  raising  the  wheel  head,  while  the 
swivel  head  is  set  over  to  the  desired  angle. 

As  a  general  thing,  the  side  teeth  of  milling  cutters  require 
grinding  but  seldom,  owing  to  the  fact  that  most  of  the  cut- 

296 


CUTTER   SHARPENING 

ting  is  done  by  the  peripheral  teeth.  In  some  cases,  however, 
the  side  teeth  require  sharpening,  it  being  obvious  that  this  is 
imperative  with  new  cutters  that  have  never  been  backed  off. 
Side  teeth  are  sharpened  in  two  ways,  that  is  to  say, 
with  the  face  or  the  periphery  of  the  wheel.  For  some  milling 
operations,  the  periphery  of  the  wheel  is  to  be  preferred 
as  it  gives  a  better  cutting  clearance.  Grinding  under  these 
conditions  is  illustrated  in  Fig.  155  which  shows  an  attach- 


Fig.  155. — Grinding  the  side  teeth  of  a  milling  cutter  on  the  periphery  of  the 
wheel  on  a  Brown  &  Sharpe  cutter  grinding  attachment. 

ment  for  this  purpose  on  the  Brown  &  Sharpe  cutter  grinder 
depicted  in  Figs.  150  and  152.  The  cutter  is  held  on  the 
end  of  an  arbor  that  fits  in 'the  head  and  is  fed  back  and 
forth  by  the  lever  seen  in  the  lower  part  of  the  illustration. 
The  guide  finger  at  the  right  locates  the  teeth. 

297 


ABRASIVES  AND  ABRASIVE  WHEELS 


The  operation  of  sharpening  side  teeth  with  the  side  of 
the  wheel  is  illustrated  in  Fig.,  156.  The  work  is  held  on 
the  end  of  an  arbor  which  fits  the  swivel  head  and  fed  back 
and  forth  past  the  face  of  the  wheel.  The  machine  is  a 
Cincinnati  grinder  and  its  makers  give  the  following  direc- 
tions for  setting  up  for  this  operation. 

"After  the  cutter  is  placed  in  position  as  above  described, 
the  head  should  be  set  to  zero  and  the  cutter  set  central 
by  means  of  the  centering  gauge.  The  tooth-rest  is  next 


Fig.  156. — Grinding  the  side  teeth  of  a  milling  cutter  using  the  side  of  the 
wheel  on  a  Cincinnati  grinder. 

adjusted  and  the  head  depressed  to  give  the  proper  angle 
of  clearance.  The  knee  of  the  machine  is  next  set  to  90-1/2 
degrees  so  that  the  grinding  is  done  with  the  down  side  of 
the  wheel,  the  upper  side  clearing.  Should  the  tooth  next 

298 


CUTTER   SHARPENING 

to  the  one  being  ground  strike  the  wheel,  the  table  should 
be  raised  to  make  the  clearance  desired.  The  above  applies 
to  the  grinding  of  right  side  teeth.  In  grinding  the  left  side 
teeth,  the  operation  is  reversed  and  the  knee  set  to  89-1/2 
degrees  so  that  the  grinding  is  done  with  the  up  side  of  the 
wheel  instead  of  the  down  side." 

Another  device  often  made  use  of  in  grinding  the  side 
teeth  of  milling  cutters  is  shown  in  Fig.  157  and  is  called  a 
universal  head.  These  heads  are  very  handy  for  a  diversity 


Fig.  157. — Universal  head  for  grinding  milling  cutters,  etc. 

of  grinding  operations.  The  machine  shown  is  a  Walker 
grinder  and  the  operator  is  grinding -the  end  teeth  of  a 
butt  mill.  This  is  held  on  a  short  arbor  which  is  located 
in  the  vee  block  of  the  universal  head.  The  head  is  tilted 
to  impart  the  desired  angle  and  the  teeth  are  located  by 
means  of  the  guide  finger  which  is  strapped  to  the  platen 
of  the  machine. 

On  first  thought,  it  might  seem  that  a  large  machine 
would  be  necessary  to  sharpen  large  inserted-tooth  milling 

299 


ABRASIVES  AND  ABRASIVE  WHEELS 

cutters.  This  is  not  the  case,  however,  as  they  are  readily 
sharpened  on  ordinary  cutter  grinding  machines.  Fig.  158 
illustrates  the  operation  of  sharpening  the  face  teeth  of  a 
large  mill  on  a  Cincinnati  grinder.  The  cutter  is  mounted 
on  a  shank  held  in  the  swivel  head  spindle  and  the  swivel 


Fig.  158. — Grinding  a  large  inserted-tooth  milling  cutter  on  a 
Cincinnati  grinder. 


head  is  depressed  to  impart  the  desired  clearance.  The 
face  of  the  tooth  should  be  brought  to  a  horizontal  position 
and  the  tooth-rest  adjusted  to  bear  on  it. 

It  is  a  well-known  fact  that  the  corners  of  the  teeth  of 
any  face  mill  wear  readily  and  experience  has  proven  that 
excellent  results  are  obtained  by  rounding  these  corners. 
A  corner  relieved  in  this  manner  is  illustrated  in  Fig.  159 
and  the  operation  of  grinding  it  on  a  Cincinnati  grinder  is 

300 


CUTTER   SHARPENING 

illustrated  in  Fig.  160.  The  cut  is  obtained  by  swiveling 
the  head  45  degrees,  22-1/2  degrees  and  67-1/2  degrees. 
While  grinding  large  cutters,  it  is  often  necessary  to  swivel 


Fig.  159. — Relieved  corners  on  face-mill  tooth 

both  the  table  and  the  head  to  allow  for  clearance.  In 
this  method  the  angle  is  obtained  by  a  combination  of  both 
dials. 


Fig.  1 60. — Cincinnati  grinder  set  up  to  relieve  corners  of  cutter  teeth. 
301 


ABRASIVES  AND  ABRASIVE  WHEELS 


The  operation  of  sharpening  the  peripheral  teeth  of 
large  end  mills  is  shown  in  Fig.  161.  By  referring  to  the 
illustration,  it  is  seen  that  the  tooth-rest  is  fastened  to 
the  top  of  the  swivel  head  which  avoids  interference  with 


Fig.  161. — Grinding  the  peripheral  teeth  of  a  large  milling  cutter  on  a 
Cincinnati  grinder. 


the  grinding-wheel  head.  The  angle  for  clearance  is  ob- 
tained from  the  graduations  on  the  swivel  head. 

As  the  illustrations  show,  cup  wheels  are  used  in  grinding 
these  large  cutters.  As  the  grinding  is  done  with  the  face 
of  the  wheel,  it  is  obvious  that  a  straight  surface  is  obtained. 
This  is  considered  a  decided  advantage  in  these  large  cut- 
ters as  it  insures  the  maximum  amount  of  wear. 

An  important  branch  of  cutter  grinding  consists  of  sharp- 
ening the  so-called  formed  cutters  as  used  for  milling  irregu- 
lar outlines.  While  an  ordinary  milling  cutter  is  ground  by 

302 


CUTTER   SHARPENING 

cutting  away  its  periphery,  a  different  method  must  be 
followed  with  formed  cutters  as  the  outline  is  often  of  such 
a  complicated  shape  that  it  would  be  impossible  to  grind 
it.  The  relief  of  these  cutters  is  in  the  form  of  regular 
curves,  and  they  can  readily  be  sharpened  by  grinding 
away  the  dulled  part  of  the  tooth  face.  The  principle  is 
illustrated  in  Fig.  162,  wherein  A  is  the.  cutter  and  B  the 
grinding  wheel.  In  grinding  formed  cutters  the  dotted 


Fig.  162.— Principle  involved  in  grinding  formed  cutters. 

line  C,  which  is  a  continuation  of  the  wheel  face,  must  pass 
through  the  center  of  the  cutter.  Otherwise  the  cutter 
will  not  mill  exactly  the  form  for  which  it  was  designed. 

303 


ABRASIVES  AND  ABRASIVE  WHEELS 

This  is  an  important  point  in  the  grinding  of  formed  cutters 
that  is  sometimes  overlooked. 

The  operation  of  grinding  a  formed  cutter  is  shown  in 
Fig.  163.    The  work  is  done  on  a  Brown  &  Sharpe  formed 


Fig.  163. — Grinding  a  formed  cutter  on  a  Brown  &  Sharpe  formed-cutter 
grinding  attachment. 

cutter-grinding  attachment  that  is  fitted  to  the  company's 
regular  cutter  grinder  as  shown  in  Fig.  150.  The  work  is 
held  on  an  arbor  between  two  centers  and  the  cutter  is 

304 


CUTTER  SHARPENING 

indexed  around  by  means  of  the  worm  wheel  seen  in  the 
illustration. 

The  first  step  in  setting  up  the  machine  for  grinding 
cutters  of  this  type  is  to  see  that  the  face  of  the  wheel  is 
perfectly  true.  As  a  matter  of  fact,  it  is  a  good  plan  to 
true  the  face  of  the  wheel  every  time  it  is  placed  on  the 
spindle.  Next,  the  center  must  be  brought  in  line  with  the 
face  of  the  wheel.  After  the  cutter  is  in  position  on  its 
arbor,  the  wheel  is  adjusted  to  the  correct  depth  and  one 
tooth  fed  around  radially  until  it  strikes  the  wheel.  Then 
the  index  pin  is  located.  The  cut  taken  should  be  com- 
paratively light  as  it  is  an  easy  matter  to  burn  the  teeth 
of  the  cutters  in  question,  even  with  the  best  wheels  ob- 
tainable. One  tooth  should  be  ground  at  a  time  with  a 
fairly  rapid  reciprocating  motion  until  the  wheel  ceases  to 
spark  heavily.  After  all  the  teeth  have  been  ground  enough 
to  insure  their  being  sharp,  the  cutter  should  be  gone 
around  once  or  twice  with  a  slight  cut  to  make  sure  that  the 
grinding  has  left  the  teeth  evenly  spaced.  Otherwise,  only  a 
few  of  the  teeth  will  cut  after  the  cutter  is  put  in  operation. 

While  the  operation  of  sharpening  milling  cutters  of  any 
kind  is  comparatively  simple,  care  should  be  exercised  in 
the  selection  of  the  wheels  used  which  should  be  free  cutting 
and  made  of  an  alumina  abrasive,  since  the  work  is  steel 
grinding.  It  should  also  be  borne  in  mind  that  wheels  for 
sharpening  high-speed-steel  cutters  should  be  somewhat 
coarser  than  those  used  for  sharpening  carbon-steel  cutters. 
Again,  the  cup-and-saucer  wheels  used  for  sharpening  both 
plain  and  formed  cutters  should  be  somewhat  softer  than 
the  disk  wheels  so  commonly  used  for  sharpening  peripheral 
teeth.  The  following  wheels  have  been  found  to  give  good 
results  in  cutter  grinding.  The  gradings  are  according  to 
the  writer's  grade  scale.  For  high-speed-steel  cutters,  36 
to  46  grit,  4  to  7  grade.  For  carbon-steel  cutters,  50  to 
60  grit,  4  to  7  grade. 

After  the  peripheral  teeth  of  an  ordinary  milling  cutter 
have  been  sharpened  several  times,  the  tooth  land  becomes 

3°S 


ABRASIVES  AND  ABRASIVE  WHEELS 

so  wide  that  the  clearance  for  chips  is  practically  ground 
away,  in  which  case  the  cutter  is  consigned  to  the  scrap 
heap  or  annealed  and  re-cut  on  the  milling  machine.  This 
process  generally  destroys  the  size  of  the  hole,  and,  again, 
many  cutters  are  lost  in  this  manner  through  fire  cracking. 
Milling  cutters  can  be  successfully  re-cut,  without  an- 
nealing them,  on  the  attachment  illustrated  in  Fig.  163  or 
on  the  surface  grinder,  in  which  case  it  is  understood  that 


^-Grinding  Wheel 


Fig.  164. — Method  followed  in  re-cutting  milling  cutters  without 
annealing  them. 

they  are  held  on  an  arbor  between  centers.  The  method 
followed  in  re-cutting  cutters  without  annealing  them  is 
illustrated  in  Fig.  164.  After  the  cutter  is  placed  on  an 
arbor  and  the  arbor  located  between  centers,  the  first  step 
is  to  grind  grooves  as  shown  at  A.  The  illustration  is  self- 
explanatory.  The  wheel  used  for  this  work  should  be  of 
medium  grade  in  shellac  bond  about  40  to  50  grit.  After 
the  cutter  has  been  gone  around  and  all  the  teeth  cut  out, 

306 


CUTTER   SHARPENING 


the  next  operation  is  to  grind  away  the  superfluous  stock 
as  shown  at  B.  This  work  is  done  with  a  wheel  in  46  grit 
on  the  writer's  6  grade.  The  face  of  the  wheel  is  trued  to 
produce  the  desired  angle  to  the  teeth. 

The  operation  is  simple  and  after  a  little  practice,  the 
average  operator  can  secure  excellent  results  through  the 
exercise  of  a  little  care.  In  gashing  out  the  teeth,  one  tooth 
should  be  operated  on  at  a  time  and  several  cuts  taken  to 
bring  the  gash  to  the  required  depth.  In  the  re-cutting 
operation  with  the  beveled  wheel,  the  depth  of  cut  should 


Fig.  165. — Steps  taken  in  re-cutting  a  milling  cutter  without  annealing. 

not  be  deep  enough  to  cause  the  wheel  to  burn  the  work. 
In  the  latter  operation  also,  one  tooth  should  be  worked 
on  at  a  time  until  it  is  ground  to  the  required  depth  as  this 
practice  will  give  better  results  than  can  be  obtained  by 
taking  a  small  cut  from  each  tooth,  one  after  another. 

Upon  first  trial,  the  operator  will,  no  doubt,  burn  and 
ruin  a  few  cutters,  but  a  little  practice  will  make  him  pro- 
ficient. In  Fig.  165,  two  cutters  are  shown.  Cutter  A 
has  been  gashed  only  while  B  shows  the  finished  cutter  ready 
to  be  put  to  use  again.  The  side  teeth  can  be  cut  if  neces- 
sity demands,  but  since  these  teeth  are  seldom  ground, 
they  are  rarely  worn  to  the  extent  of  needing  re-cutting. 

307 


CHAPTER  TWENTY-ONE 

SAW   SHARPENING 

Band  saws  and  circular  saws — Operation  of  band-saw  sharpening  machine 
— Sharpening  band  saws — Grinding  in  new  teeth — Care  of  machine — 
Selection  of  wheels  for  saw  gumming — Machines  for  sharpening  cold  saws 
— Sharpening  hack-saw  blades. 

WHEN  we  stop  a  moment  to  consider  the  vast  amount 
of  timber  that  is  annually  cut  and  converted  into 
lumber  for  various  purposes,  it  is  easy  to  see  why  saw  sharp- 
ening, or  saw'  gumming  as  it  is  termed  in  lumber  mills  end 
other  wood-working  establishments,  is  an  extensive  trade 
in  itself.  A  man  who  sharpens  wood-working  saws  is  in- 
variably called  a  filer,  although  he  seldom  uses  a  file  in  his 
work,  and  the  room  where  the  saws  are  repaired  is  called 
the  filing  room.  The  name,  of  course,  dates  from  the  time 
when  the  file  was  the  only  tool  to  be  had  for  saw  sharpening 
.and,  in  common  with  many  other  misplaced  trade  terms, 
it  probably  will  endure  for  years  to  come. 

Saws  are  of  two  kinds,  that  is  to  say,  band  saws  and 
circular  saws,  and  there  are  various  types  of  each  kind. 
For  cutting  up  logs,  circular  saws  are  not  as  economical 
as  band  saws  owing  to  the  fact  that  the  former  have  to  be 
of  a  comparatively  thicker  gauge  to  insure  the  necessary 
stiffness  and  strength.  The  added  thickness,  of  course, 
makes  extra  sawdust  which  is  an  economic  waste.  Nowa- 
days, circular  saws  are  used  in  comparatively  few  mills. 
Still,  there  are  a  few  circular  mills  left  which  carry  saws 
as  large  as  6  feet  in  diameter.  Many  circular  saws  are  used 
as  cut-off  saws  for  various  purposes  such  as  cutting  long 

308 


SAW  SHARPENING 

logs  into  the  desired  lengths  before  they  are  sawed  into 
boards  and  for  edging  and  trimming  lumber,  etc. 

The  majority  of  mills"  today  are  band  mills  and  the  saws 
used  are  often  50  feet  long,  being  driven  by  two  large  pulleys, 
in  width,  they  run  from  10  to  14  inches.  A  smaller  type  of 
band  saw,  called  a  re-saw,  is  generally  about  25  feet  long 
and  from  6  to  10  inches  wide.  Many  filers  make  their  re- 
saws  from  old  hand  saws. 

Two  machines  used  for  saw  gumming  are  shown  in  Figs. 
1 66  and  167.  The  machine  shown  in  Fig.  166  is  for  sharp- 
ening band  saws,  while  the  one  shown  in  Fig.  167  is  for 


Fig.  1 66. — Type  of  machine  used  for  gumming  band  saws. 

circular  saws,  the  saw  shown  being  a  cut-off  saw  which  is 
readily  seen  from  the  shape  of  the  teeth. 

Both  types  of  machines  operate  on  practically  the  same 
principle,  that  is  to  say,  means  are  provided  for  feeding 
the  saw  under  the  wheel,  tooth  by  tooth,  and  for  lowering 

309 


ABRASIVES  AND  ABRASIVE  WHEELS 

and  raising  the  wheel  to  form  the  desired  shape  of  the  teeth. 
In  the  machine  illustrated  in  Fig.  166,  the  head  is  set  over 
at  an  angle  and  is  fed  up  and  down  by  an  adjustable  cam 
arrangement  which  can  be  set  to  form  different  kinds  of 
teeth.  The  saw  is  fed  forward  by  means  of  an  adjustable 
dog  that  pulls  the  saw  along  tooth  by  tooth  the  desired 
distance,  the  feeding  taking  place  while  the  saw  is  out  of 
the  gullet  of  the  tooth. 

The  machine  shown  in  Fig.  167  has  practically  the  same 
arrangement  for  feeding  the  saw  along,  but  the  head  travels 
straight  up  and  down.  It  also  swivels  alternately  to  form 
the  desired  angle  on  the  teeth.  Both  machines  shown  are 
fully  automatic. 

The  grinding  of  band  saws  is  divided  into  two  distinct 
operations  called  by  the  filer,  "roughing  out"  and  "pointing 
up."  The  latter  operation  is  comparatively  simple  and  re- 
quires only  a  few  cuts  around  the  saw.  This  operation 
takes  place  after  the  dull  saw  is  taken  from  the  mill.  After 
a  saw  has  been  in  use  a  few  days,  it  has  to  be  re-swaged  and 
after  this  operation  it  has  to  be  ground  again  before  it  is 
fit  for  use. 

The  operation  of  roughing  out  is  where  the  real  work  of 
the  filer  comes,  for  logs,  as  they  come  to  the  mill,  are  not 
composed  wholly  of  wood  by  any  means.  Sometimes,  in 
felling,  a  small  stone  becomes  imbedded  in  the  wood. 
Again  perhaps,  the  log  grew  on  a  farm,  and  some  thrifty 
farmer  might  have  hung  a  horseshoe,  a  piece  of  broken  chain 
or  other  bit  of  discarded  metal  in  the  crotch  of  one  of  the 
limbs,  which  in  time  grew  over  and  covered  up  the  metal. 
Logs  are  often  bound  together  in  rafts  for  floating  down 
the  river  by  wooden  cross-pieces,  held  together  by  tree- 
nails. The  holes  for  the  treenails  are  bored  with  ship 
augers  and  sometimes  an  auger  is  broken  off  and  left  in 
the  log.  The  rafts  are  often  chained  together  and  the  chains 
are  spiked  to  the  logs.  From  this  it  is  seen  that  many 
factors  are  present  to  keep  the  filer  continually  on  the 
job  for  when  a  saw,  traveling  at  a  high  speed,  strikes  one 

310 


SAW  SHARPENING 

of  these  obstructions  it  sometimes  happens  that  every  tooth 
is  literally  stripped  off  nearly  down  to  the  bottom  of  the 
gullets. 

When  accidents  of  this  kind  happen,  the  operation  of 
roughing  out  the  saw  is  in  order.    This  requires  much  grind- 


Fig.  167. — Type  of  machine  used  for  gumming  circular  saws. 

ing  as  every  tooth  has  to  be  ground  in  again,  to  the  desired 
depth,  which  takes  many  hours  of  heavy  grinding.  When 
the  filer  makes  a  new  saw  from  a  blank,  which  is  common 
practice  in  some  parts  of  the  country,  the  roughing  out 


ABRASIVES  AND  ABRASIVE  WHEELS 

operation  also  takes  place.    It  is  first  necessary  to  stamp  the 
teeth  in  the  saw  and  then  grind  them  to  the  correct  shape. 
The   stamping  operation   is  essential,   otherwise  the  feed . 
dog  would  have  no  depressions  to  grip  to  carry  the  saw 
along. 

From  the  above,  it  is  seen  that  the  filer  in  a  large  band 
mill  works  under  difficulties  and  aside  from  the  above 
hindrances  he  has  other  troubles  to  contend  with.  It  is, 
of  course,  necessary  that  the  filing  room  be  in  close  prox- 
imity to  the  mills  on  which  the  saws  are  used.  The  ideal 
location  for  the  filing  room  is  in  a  detached  room  on  the 
level  with  the  mill  floor.  The  object  of  the  detached  build- 
ing is  to  eliminate,  as  much  as  possible,  the  vibration  which 
is  always  a  detriment  to  good  grinding  of  any  kind  what- 
soever. 

Another  factor  that  is  the  cause  of  much  trouble  in  the 
filing  room  is  that  the  engine  that  runs  the  mill  also  runs 
the  line  shaft  in  the  filing  room.  Thus,  when  the  saw  goes 
through  a  large  log  the  speed  of  the  engine  is  lowered  a 
few  revolutions  per  minute  before  the  governor  can  feed 
more  steam  to  compensate  for  the  extra  load.  While  the 
engine  lowers  its  speed  a  few  revolutions  a  minute,  it  is 
readily  seen  that  the  grinding  wheel  on  the  saw-gumming 
machine  is  lowered  in  speed  in  a  greater  ratio  as  it  runs 
correspondingly  faster  than  the  engine.  This  factor  of 
uneven  wheel  speed  interferes  with  good  results  and  for 
this  reason  the  mills,  where  careful  planning  is  in  evidence, 
are  equipped  with  small  independent  engines  for  supplying 
power  to  the  filing  room. 

Saw-grinding  machines  are  very  seldom  equipped  with 
means  for  carrying  away  the  dust  caused  by  grinding,  and 
for  this  reason  they  should  receive  careful  attention.  The 
wheel  spindle  boxes  should  be  examined  frequently  and  the 
wear  taken  up  when  necessary,  for  a  loose  wheel  spindle 
cannot  be  depended  upon  for  the  best  results.  The  cams 
and  their  rolls  should  be  examined  and  oiled  frequently. 
The  cams  wear  out  of  shape  in  time:  thus  they  fail  to  pro- 

312 


SAW  SHARPENING 

duce  the  proper  kind  of  tooth.  A  worn  cam  lets  the  wheel 
down  into  the  gullet  of  the  tooth  too  abruptly,  which  not 
only  spoils  the  shape  of  the  tooth,  but  wears  away  the 
wheel  too  rapidly. 

Great  care  should  be  used  in  the  selection  of  wheels 
for  saw  gumming  because  inferior  abrasives  often  burn  and 
case  harden  the  saws,  causing  them  to  crack.  If  a  crack 
shows  up  at  the  bottom  of  a  tooth,  the  only  thing  to  do  is 
to  cut  the  tooth  out  and  braze  in  a  new  one  which  is  an 
expensive  operation.  These  wheels  should  be  of  an  alumina 
abrasive  and  soft  enough  to  cut  freely,  but  not  soft  enough 
to  wear  out  too  fast.  The  grade  depends  principally  on  the 
condition  the  machine  is  in  and  other  local  factors  such  as 
undue  vibration.  Too  much  vibration  wears  out  the  wheels 


V     ' .  '-./'• ' ,  '; 


c 

Fig.  1 68. — Three  types  of  wheels  used  for  saw  gumming. 

readily  and  a  harder  wheel  must  be  used  than  could  be 
employed  under  more  favorable  conditions.  The  wheels 
used  for  this  work  run  from  30  to  46  grit  and  7  to  10  grade 
according  to  the  writer's  grade  scale.  Combination  grit 
wheels  with  a  base  of  30  or  36  are  excellent  for  this  purpose. 
There  are  three  shapes  of  wheels  used  for  saw  gumming, 
as  illustrated  in  Fig.  168.  A  is  a  plain  straight  wheel,  B 
is  tapered  on  both  sides  while  C  is  a  shape  called  a  Covel 
saw  gummer.  There  is  a  difference  of  opinion  among  filers 
as  to  which  shape  is  the  best  to  use.  Some  filers  get  ex- 
cellent results  with  plain  straight  wheels,  while  others  in- 

313 


ABRASIVES  AND  ABRASIVE  WHEELS 

sist  that  the  tapered  cutting  side  gives  a  better  wheel  clear- 
ance and  there  is,  no  doubt,  some  truth  in  the  claim. 

Re-saws  are  ground  in  exactly  the  same  manner  as  are 
large  band  saws  with  the  exception  that  the  machine  used 
is  comparat  vely  smaller.  A  re-saw  grinding  operation  in 
a  planing  mill  is  shown  in  Fig.  169.  The  filer  in  the  planing 
mill  has  comparatively  few  troubles  compared  to  his  brother 


Fig.  169. — Grinding  a  small  band  re-saw. 

in  the  big  band  mill,  for  the  saws  in  planing  mills,  aside  from 
cutting  through  an  occasional  nail,  are  seldom  put  to  severe 
use. 

A  different  type  of  machine  than  the  one  heretofore  shown 
for  sharpening  circular  saws  is  shown  in  Fig.  170.  This 
machine  is  used  for  sharpening  small  circular  saws  as  used 
in  planing  mills  and  furniture  factories.  The  saw  is  located 
in  a  horizontal  position.  This  machine  is  not  automatic 
as  far  as  the  feed  is  concerned  as  the  operator  has  to  space 
the  teeth  around  by  means  of  the  lever  operated  by  his 
left  hand.  For  small  saws,  these  semi-automatic  machines 
give  excellent  results.  The  same  wheels  are  used  for  re-saws 

314 


SAW  SHARPENING 

and  small  circular  saws  as  are  used  for  larger  saws,  the  only 
exception  being  that  the  grits  are  somewhat  finer. 

Another  important  branch  of  saw  sharpening  consists 
of  grinding  metal  cutting  saws  as  shown  in  Fig.  171.  These 
are  often  termed  "cold  saws"  and  are  used  for  cutting 


t  •  •  t 


Fig.'  170. — Metal  cutting  or  cold  saw  used  for  cutting  large  steel  sections. 

bar  stock,  structural-steel  sections,  rails,  etc.  They  are 
also  frequently  used  in  steel  foundries  for  cutting  away  the 
sprues  from  large  castings.  As  may  be  imagined,  they  are 
often  put  to  severe  usage  and  for  this  reason  they  require 
frequent  grinding. 

The  operation  of  sharpening  the  saw  shown  in  Fig.  171 
is  il'ustrated  in  Fig.  172.  This  machine  is  a  product  of  the 
Matteson  Mfg.  Co.,  Chicago,  and  is  designed  on  the  prin- 
ciple involved  in  the  saw-sharpening  machines  previously 


ABRASIVES  AND  ABRASIVE  WHEELS 

described  in  this  chapter.  That  is  to  say,  it  has  means 
for  feeding  the  wheel  with  an  up-and-down  motion  while  the 
saw  is  fed  onward,  tooth  by  tooth,  by  a  feed  dog.  These 
motions  are  automatic. 

The  operation  of  sharpening  cold  saws  is  somewhat  simi- 
lar to  re-cutting  milling  cutters  as  previously  described, 
because  two  cuts  are  generally  taken;  one  to  grind  out  the 
gullets  and  a  following  cut  to  sharpen  the  teeth,  giving 


Fig.  171. — Type  of  semi-automatic  machine  used  for  sharpening  small 
circular  saws. 


them  the  proper  relief  at  the  same  time.  For  grinding  out 
the  gullets,  the  wheel  is  beveled  to  the  correct  angle,  the 
wheel  being  dropped  directly  into  the  tooth.  For  sharpening 
the  periphery  of  the  saw,  the  wheel  is  beveled  slightly; 
only  just  enough  to  insure  the  proper  cutting  clearance. 

Another  machine  extensively  used  for  sharpening  cold 
saws  is  shown  in  Fig.  173.  This  is  made  by  the  Newton 
Machine  Tool  Works,  Philadelphia.  The  machine  is  self- 
contained  and  electrically  driven  by  means  of  a  motor  placed 

316 


SAW  SHARPENING 

on  a  supplementary  base  while  the  rest  of  the  mechanism 
is  supported  by  a  cast-iron  column. 

This  machine  is  fully  automatic  in  operation  beyond 
locating  the  saw  and  setting  the  hand  adjustment  for  depth 
of  cut.  To  insure  each  tooth  being  of  the  correct  contour, 


Fig.  172. — Sharpening  a  cold  saw  on  a  Matteson  saw-sharpening  machine. 

the  feeding  pawl  is  set  so  that  the  wheel  grinds  both  the 
back  and  the  front  of  the  tooth  in  the  roughing-out  opera- 
tion. In  grinding  saws  in  which  a  tooth  or  two  has  been 
broken  out  (which  is  not  infrequent)  an  auxiliary  feed  pawl  is 
provided.  This  pawl  engages  the  next  tooth  back  of  the 
break. 


ABRASIVES  AND  ABRASIVE  WHEELS 


Fig.  173. — Newton  self-contained  automatic  cold-saw  sharpening  machine. 


SAW  SHARPENING 

Broadly  speaking,  the  operation  of  sharpening  cold  saws 
is  simp'e  and  it  is  easily  carried  out  if  a  few  simple  pre- 
cautions are  taken.  In  the  first  place,  these  saws  should  be 
sharpened  frequently.  It  should  be  borne  in  mind  that  they 
are  really  no  more  or  less  than  huge  milling  cutters  and  as 
such  they  should  be  given  careful  attention.  When  slightly 
dull,  they  cannot  work  to  maximum  efficiency,  but  if  they 
are  kept  sharp  they  will  yield  excellent  results.  Several 
saws  for  each  machine  should  be  kept  on  hand  and  dull 
saws  should  be  replaced  with  sharp  ones  at  frequent  intervals. 

The  wheels  used  for  sharpening  cold  saws  should  be  of 
a  free-cutting  nature  and  at  the  same  time  they  should 
hold  their  shape  well.  This  applies  to  the  wheels  used  for 
grinding  the  periphery  of  the  teeth  as  well  as  those  used  for 
forming  out  the  gullets.  As  the  grinding  in  question  is 
steel,  the  wheels  should  be  made  of  an  alumina  abrasive. 
Grits  from  40  to  60  in  the  writer's  grades  ranging  from  10 
to  1 2  generally  give  good  results. 

The  machine  shown  in  Fig.  174  was  designed  especially 
for  sharpening  hack-saw  blades  and  the  slow-running  band 
saws  as  used  at  the  present  day  for  cutting  metals  of  various 
kinds.  Some  years  ago,  when  hack-saw  blades  were  made 
of  carbon  steel  they  were  thrown  away  as  soon  as  the  teeth 
became  too  dull  for  practical  use.  At  the  present  time, 
however,  when  the  majority  of  hack-saw  blades  are  made 
of  high-speed  steel,  it  is  evident  that  the  average  manufac- 
turing plant's  expenditure  for  blades  under  such  conditions 
is  comparatively  high  and  attention  has  been  directed  to 
reclaiming  the  worn  blades. 

The  machine  in  question  is  designed  and  made  by  the 
Wardwell  Mfg.  Co.,  Cleveland,  Ohio,  and  its  operation  is 
comparatively  simple.  As  the  illustration  shows,  it  is  not 
unlike  the  machines  previously  described  for  sharpening 
wood- working  saws.  The  machine  is  provided  with  a  main 
drive  which  extends  across  the  back  of  the  frame  and  power 
is  transmitted  by  means  of  a  belt  to  the  shaft  seen  in  the 
foreground,  upon  which  the  grinding  wheel  is  mounted. 

3-IQ 


ABRASIVES  AND  ABRASIVE  WHEELS 

This  wheel  is  comparatively  thin,  is  made  in  elastic  bond, 
and  is  of  medium  grit  and  grade. 

The  grinding-wheel  shaft,  or  spindle,  is  suspended  at 
the  end  of  an  arm,  the  opposite  end  of  which  swings  in 
pivoted  bearings,  placed  well  part  to  reduce  side  motion  to 
a  minimum.  This  feature  is  necessary  to  insure  correct 
spacing  of  the  saw  teeth.  The  arm  is  supported  in  a  seg- 


Fig.  174. — Wardwell  automatic  saw-sharpening  machine. 

ment  which  allows  the  wheel  to  be  set  at  an  angle.  This 
permits  one  edge,  or  corner,  only  of  the  wheel  to  come  in 
contact  with  the  face  of  the  tooth  being  ground  while  the 
opposite  edge,  or  corner,  bears  on  the  back  of  the  tooth. 
This  action  serves  to  keep  the  wheel  dressed  constantly 
so  that  it  always  presents  the  proper  shape  for  forming  the 
gullets  of  the  teeth. 

Two  adjustments  control  the  movements  of  the  grinding- 
wheel  head.  One  governs  the  depth  the  grinding  wheel  is 
allowed  to  sink  into  the  tooth  gullet,  while  the  other  regu- 
lates the  amount  of  cut  to  be  taken  from  the  back  of  the 
tooth.  The  last  adjustment  is  made  by  an  adjusting  screw 

320 


SAW  SHARPENING 

which  comes  in  contact  at  the  proper  time  with  a  roll  which 
bears  on  the  face  of  the  cam.  This  cam  is  adjustable  for 
forming  all  the  different  shaped  backs  of  teeth. 

Power  from  the  feed  mechanism  is  derived  from  the  main 
drive  shaft  through  a  worm  gear  to  a  shaft  at  the  left- 
hand  side  of  the  machine.  On  the  end  of  this  shaft  is  a 
slotted  eccentric  equipped  with  a  screw  feed.  This  eccentric 
governs  the  feed  of  the  blade  to  the  machine. 

The  operation  of  the  machine  is  simple  and  exact  and 
it  is  said  that  as  little  as  one-half  thousandth  of  an  inch 
can  be  removed  from  either  the  face  or  the  back  of  the 
tooth.  The  machine  is  automatic  in  operation,  and,  after 
being  started,  it  requires  no  more  attention  until  the  saw 
has  been  sharpened,  that  is,  when  grinding  a  band  saw. 
With  hack  saws,  a  group  is  placed  in  position  and  the  feed 
pawls  take  these  one  at  a  time  and  feed  them  through  the 
machine.  A  group  of  hack-saw  blades  are  placed  in  the 
machine,  being  held  by  spring  tension.  The  feed  pawl  bears 
on  the  inner  blade  only,  thus  as  soon  as  this  is  fed  out  of 
the  way,  the  spring  action  forces  another  in  a  position  to 
be  fed  forward. 

The  blades  are  fed  along  by  a  double-pawl  arrangement. 
Two  pawls  work  at  the  same  time,  one  on  each  side  of  the 
grinding  wheel.  The  one  on  the  right  draws  the  blade  in 
and  starts  the  grinding  of  the  first  tooth,  while  the  other  on 
the  left  draws  the  blade  clear  of  the  grinding  wheel  and  dis- 
charges it. 


INDEX 


Abrasive  action,  133. 

Abrasive  discs,  manufacture  of,  169. 

Abrasive  discs,  materials  used,  173. 

Abrasive  discs,  selection  of,  173. 

Abrasive  discs,  testing,  174. 

Abrasive  paper  and  cloth,  coating- 
machine  for  making,  167. 

Abrasive  paper  and  cloth,  early  manu- 
facture of,  167. 

Abrasive  paper  and  cloth,  grits  of,  89. 

Abrasive  paper  and  cloth,  sizes  and 
numbers  of,  168. 

Abrasive  paper  and  cloth,  uses  of,  166. 

Abrasive  temper,  52. 

Abrasives,  artificial,  37. 

Abrasives,  natural,  13. 

Abrasives  used  for  die  grinding,  192. 

Accidents,  blame  for,  164. 

Accidents  caused  by  tight  wheel 
bushings,  153. 

Accidents  caused  by  work  rest,  155. 

Acheson,  Edward  G.,  38. 

Action,  abrasive,  133. 

Action,  grindstone,  124. 

Adamite,  63. 

Adaptability  of  cylinder  grinder,  261. 

Adapting  wheel  for  surface  grinding. 
199. 

Advantage  of  coarse  feed  marks  in 
grinding,  181. 

Advantages  of  combination  grits,  89. 

Advantages  of  re-bushing  grinding 
wheels,  139. 

Advantages  of  using  large  grinding 
wheels,  130. 

Allowance  for  finish  chip,  223. 

Allowance  for  internal  grinding,  253. 

Allowances  for  grinding,  220. 

Aloxite,  58. 

Aloxite,  characteristics  of,  60. 

Aloxite,  color  of,  60. 

Aloxite,  furnace,  58. 


Aloxite,  furnace,  power  required  to 
operate,  58. 

Aloxite  grain,  preparation  of,  59. 

Aloxite,  how  crushed,  59. 

Aloxite  ingot,  59. 

Aloxite  ingots,  how  broken,  59. 

Aloxite,  process  of  making,  58. 

Aloxite,  purity  of,  59. 

Aloxite,  uses  of,  60. 

Aloxite,  where  made,  58. 

Alumina,  artificial,  Dollner's,  51. 

Alumina,  percentage  of  in  emery,  17. 

Alundum,  57. 

Alundum  furnace,  horsepower  re- 
quired to  operate,  57. 

Alundum,  how  crushed,  57. 

Alundum  pigs,  57. 

Alundum,  process  of  making,  57. 

Alundum,  uses  of,  58. 

Alundum,  varieties  of,  58. 

Alundum  varieties,  how  designated, 
58. 

American  corundum,  25. 

American  emery,  discovery  of,  16. 

Amount  ^for  finishing  in  crankshaft 
grinding,  279. 

Amperage  of  Carborundum  furnace, 
40. 

Analysis  of  .Corubin,  51. 

Analysis  of  corundum,  23. 

Angular  cutters,  grinding,  295. 

Angular  grit,  64. 

Angular  grit,  composition  of,  64. 

Angular  grit,  sizes  of,  64. 

Angular  grit,  uses  of,  64. 

Arkansas  sharpening  stones,  35. 

Arkansas  sharpening  stones,  com- 
position of,  35. 

Arkansas  sharpening  stones,  uses  of, 
35- 

Arkansas  sharpening  stones,  varieties 
of,  35- 

Arkansas  sharpening  stones,  where 
found,  35. 


323 


INDEX 


Artificial  abrasive,  Werlein's,  61. 

Artificial  abrasives,  37. 

Artificial  alumina,  Dr.  G.  Dollner's, 

Si- 

Artificial  corundum,  47. 

Artificial  corundum,  development  of, 

48. 
Artificial  corundum,  first  successful 

production  of,  48. 
Artificial  corundum,  Jacobs'  process 

for  making,  56. 

Artificial  corundum,  temper  of,  56. 
Artificial  corundum,  when  first  made, 

47,  48. 

Artificial  sharpening  stones,  83. 
Automobile  engine  cams,  types  of,  280. 
Axe  grinding,  125. 
Axe  grinding,  advantages  of  grinding 

wheels  in,  126. 
Axe  grinding,  future  of  grinding  wheel 

for,  127. 
Axe  grinding,  time  consumed,  126. 

B 

Backrest,  setting,  Norton,  226. 
Backrest,  solid,  Norton,  226. 
Backrest,  spring,  Brown  &  Sharpe, 

227. 
Backrest,  universal,  Brown  &  Sharpe, 

228. 

Backrests,  kinds  of,  226. 
Balance  wheel,  234. 
Balancing  device,  Landis,  235. 
Balancing  grinding  wheels,  76. 
Balas  ruby,  47. 
Band  re-saws,  309. 
Band  re-saws,  grinding,  314. 
Band  saws,  308. 
Barrel  corundum,  22. 
Bauxite,  53,  57. 
Bauxite,  color  of,  53. 
Bauxite,  discovery  of,  53. 
Bauxite,  origin  of  name,  53. 
Bauxite,  where  found,  53,  54. 
Belgian  razor  hone,  35. 
Belts,  garnet  paper,  testing,  172. 
Berthier,  P.,  53. 
Blame  for  accidents,  164. 
Blanchard  continuous  reading  caliper 

gauge,  212. 
Blanchard  grinder,  chuck  speed  for, 

211. 


Blanchard  grinder,  locating  work  on, 

211. 

Blanchard  grinder,  operation  of,  212. 

Blanchard  grinder,  wheels  for,  212. 

Blanchard  grinder,  wheel  speed,  211. 

Blanchard  surface  grinding  machine, 
208. 

Blanchard  surface  grinder,  samples  of 
work  done  on,  210. 

Bond  of  grinding  wheels,  66. 

Bonding  materials,  66. 

Bonding  materials,  how  tested,  67. 

Bonds,  grinding  wheel,  how  standard- 
ized, 67. 

Boro-Carbone,  62. 

Boro-Carbone,  characteristics  of,  62. 

Boro-Carbone,  color  of,  62. 

Boro-Carbone,  uses  of,  62. 

Boro-Carbone,  where  made,  62. 

Bort  diamonds,  31. 

Branch  pipes,  size  of  for  dust-col- 
lecting system,  146. 

Breakage,  grinding  wheels,  causes  of, 
151 

Breaking  Aloxite  ingots,  59. 

Brown  &  Sharpe  cutter  grinder,  290. 

Brown  &  Sharpe  cutter  grinding  at- 
tachment, 297. 

Brown  &  Sharpe  formed-cutter  grind- 
ing attachment,  304. 

Brown  &  Sharpe  spring  backrest,  227. 

Brown  &  Sharpe  surface  grinder,  188. 

Brown  &  Sharpe  universal  backrest, 
228. 

Brown  &  Sharpe  universal  grinder, 
236. 

Burning  a  Carborundum  furnace,  40. 

Bushing  grinding  wheels,  75. 

By-product  of  Carborundum  furnace, 
40* 


Calender  rolls,  causes  of  wear  of,  264. 
Calender   rolls,  early,  how  finished, 

265. 

Calender  rolls,  how  ground,  269. 
Calender  rolls,  largest  stack  of,  263. 
Calender  rolls,  old  installation,  265. 
Caliper    gauge,    continuous-reading, 

Blanchard,  212. 
Cam  grinder,  leaders  for,  283. 
Cam-grinding    attachment,    Norton, 

280. 


324 


INDEX 


Cam-grinding,  effect  of  wheel  wear 

in,  285. 

Cam-grinding  leaders,  how  made,  284. 
Cam-grinding,  steady-rests  for,  282. 
Cam-grinding,  wheels  for,  283. 
Cams,  types  of  in  automobile  engines, 

280. 

Canadian  corundum,  21. 
Canadian  corundum  deposits,  21. 
Carbide  of  silicon,  38. 
Carbide  of  silicon,  German,  46. 
Carbonado,  fracture  of,  32. 
Carbonado,  specific  gravity  of,  29. 
Carbonado,  uses  of,  32. 
Carbonado,  where  found,  32. 
Carborundum,  cleavage,  41. 
Carborundum  cloth,  168. 
Carborundum,  color  of,  41. 
Corborundum,  composition  of,  38. 
Carborundum  crystals,  shape  of,  41. 
Carborundum  for  steel  grinding,  45. 
Carborundum,  fracture  of,  41. 
Carborundum  furnace,  38. 
Carborundum  furnace,  amperage,  40. 
Carborundum  furnace,  burning,  40. 
Carborundum  furnace,  by-product  of, 

40. 

Carborundum  furnace,  charge  of,  39. 
Carborundum  furnace,  contents  of,  40. 
Carborundum  furnace,  heat  of,  40. 
Carborundum  furnace,  how  charged, 

39- 

Carborundum  furnace,  voltage,  40. 
Carborundum  grain,  numbers  of,  44. 
Carborundum,  hardness  of,  41. 
Carborundum,  how  crushed,  42. 
Carborundum,  how  graded,  43. 
Carborundum,  how  purified,  42. 
Carborundum,  impurities  of,  42. 
Carborundum  paper,  168. 
Carborundum  powder,  how  graded, 

44- 

Carborundum,  process  of  making,  39. 
Carborundum,  raw  materials,  38. 
Carborundum  razor  hones,  85. 
Carborundum  rubs,  86. 
Carborundum  sharpening  stones,  83. 
Carborundum     sharpening      stones, 

combination,  86. 
Carborundum  sharpening  stones,  grits 

of,  85. 
Carborundum  sharpening  stones,  how 

finished,  86. 


Carborundum  sharpening  stones,  how 

molded,  84. 

Carborundum,  specific  gravity  of,  41. 
Carborundum,  uses  of,  45. 
Carborundum,  when  discovered,  38. 
Carborundum,    why    not    found    in 

nature,  41. 
Carbosolite,  46. 
Carbosolite,  color  of,  47. 
Care  of  saw  grinding  machines,  312. 
Car-wheel   grinding,    testing    wheels 

for,  1 06. 

Case  hardening  of  saws,  cause  of,  313. 
Cause  of  chatter  marks,  232. 
Causes  of  chattering  in  roll  grinding, 

269. 

Causes  of  hard  and  soft  spots,  72. 
Center,  square,  221. 
Centers,  grinding,  240. 
Chain  link  grinding,  112. 
Change  in  grade,  effect  of,  105. 
Characteristics  of  Aloxite,  60. 
Characteristics  of  Boro-Carbone,  62. 
Characteristics  of  emery,  1 7. 
Characteristics  of  grindstones,  127. 
Characteristics  of  pressed  wheels,  68. 
Charge  of  Carborundum  furnace,  39. 
Charging  a  Carborundum  furnace,  39. 
Chatter  marks,  cause  of,  232. 
Chattering,  causes  of,  in  roll  grinding, 

269. 

Chattering,  wheel,  200. 
Chilled  iron  roll  grinding  test,  1 08. 
Chuck,  bushing,  Heald,  248. 
Chuck  for  ring  wheel,  180. 
Chuck,  magnetic,  Heald,  194. 
Chuck,  magnetic,  swivel,  194. 
Chuck,  magnetic,  taper,  194. 
Chuck  speed  for  Blanchard  grinder, 

211. 

Chucking  work  for  internal  grinder, 

247. 

Chucks,  gear,  248,  251,  252,  253. 
Chucks,  magnetic,  current  for,  197. 
Chucks,  rotary,  for  surface  grinder, 

204. 

Cincinnati  cutter  grinder,  290. 
Circular  saws,  308. 
Circular  saws,  machine  for  grinding, 

3H- 

Classes  of  diamonds,  29. 
Cleanouts  for  dust  collecting  system, 
149. 


325 


INDEX 


Clearance,  cutter,  how  obtained,  295. 

Cleavage  of  Carborundum,  41. 

Cloth,  Carborundum,  168. 

Cloth,  emery,  168. 

Coarse  feed,  advantages  of  in  grind- 
ing, 181. 

Coating-machine  for  making  abrasive 
paper  and  cloth,  167. 

Collars  for  dust  collecting  system,  de- 
sign of,  147. 

Collecting  systems,  dust,  advantages 
of,  145. 

Collector,  location  of,  for  dust  col- 
lecting system,  150. 

Color  of  Aloxite,  60. 

Color  of  bauxite,  53. 

Color  of  Boro-Carbone,  62. 

Color  of  Carborundum,  41. 

Color  of  Carbosolite,  47. 

Color  of  diamonds,  31. 

Color  of  emery,  15. 

Colors  of  sandstone,  14. 

Combination  Carbprundum  sharpen- 
ing stones,  85. 

Combination  grits,  89. 

Combination  grits,  advantages  of,  89. 

Comparative  grade  lists,  inaccuracy 
of,  91. 

Comparative  values  of  grinding 
wheels,  129. 

Comparison  of  surface  grinders,  202. 

Component  parts  of  corundum,  22. 

Component  parts  of  spinel  emery,  16. 

Composition  of  angular  grit,  64. 

Composition  of  Arkansas  sharpening 
stones,  35. 

Composition  of  Carborundum,  38. 

Composition  of  flint,  34. 

Composition  of  grinding  wheels,  65. 

Composition  of  Oxalumina,  63. 

Composition  of  quartz,  34. 

Composition  of  ruby,  48. 

Cones,  pyrometric,  72. 

Contents  of  Carborundum  furnace,4O. 

Continuous  reading  caliper  gauge, 
Blanchard,  212. 

Correct  method  of  testing  trial  wheels, 

100. 

Corubin,  analysis  of,  51. 
Corubin,  uses  of,  52. 
Corundum,  American,  25. 
Corundum,  analysis  of  23. 
Corundum,  artificial,  47. 


Corundum,  artificial,  first  successful 
production  of,  48. 

Corundum,  barrel,  22. 

Corundum,  Canadian,  21. 

Corundum,  component  parts  of,  22. 

Corundum,  Craigmont,  23. 

Corundum,  Craigmont,  when  dis- 
covered, 24. 

Corundum,  hardness  of,  22. 

Corundum,  how  crystallized,  21. 

Corundum,  how  prepared,  24. 

Corundum,  how  tested,  25. 

Corundum,  ideal,  22. 

Corundum,  origin  of  name,  20. 

Corundum,  uses  of,  29. 

Corundum,  varieties  of,  21. 

Corundum,  where  found,  21,  25,  26. 

Corundum,  why  not  used  more  ex- 
tensively, 26. 

Cost  comparisons,  grinding  wheels  and 
grindstones,  126. 

Craigmont  corundum,  23. 

Craigmont  corundum,  when  discov- 
ered, 24. 

Crank  cases,  finishing,  185. 

Crankshaft  grinder,  Landis,  275. 

Crankshaft  grinder,  radius  truing  de- 
vice, 277. 

Crankshaft  grinding,  277. 

Crankshaft  grinding,  amount  for  fin  • 
ishing,  279. 

Crankshaft  grinding,  wheels  for,  278. 

Crankshaft  grinding,  work  carrying 
fixtures  for,  275. 

Crocus,  63. 

Cross  feed  for  die  grinding,  192. 

Crowning  mechanism,  roll,  Parrel, 
268. 

Crowning  rolls,  reason  for,  267. 

Crushed  steel,  63. 

Crushed  steel,  how  made,  63. 

Crushed  steel,  sizes  of,  64. 

Crushed  steel,  uses  of,  64. 

Crushing  Aloxite,  59. 

Crushing  alundum,  57. 

Crushing  Carborundum,  42. 

Crystallization  of  corundum,  21. 

Crystallization  of  garnet,  32. 

Crystallization  of  quartz,  34. 

Crystals,  Carborundum,  shape  of,  41. 

Crystolon,  47. 

Crystolon,  how  made,  47. 

Cup  wheels  for  cutter  grinding,  302. 


326 


INDEX 


Current  for  magnetic  chucks,  197. 
Cut,  depth  of,  224. 
Cut,  depth  of  for  die  grinding,  192. 
Cutter  clearance,  how  obtained,  295. 
Cutter    grinder,    Brown    &    Sharpe, 

290. 

Cutter  grinder,  Cincinnati,  290. 
Cutter  grinder,  Walker,  299. 
Cutter  grinding  attachment,  Brown 

&  Sharpe,  297. 

Cutter  grinding,  cup  wheels  for,  302. 
Cutter  grinding,  locating  work,  291. 
Cutter  grinding,  machines  used  for, 

290. 

Cutter  grinding  sleeve,  293. 
Cutter  grinding  wheels,   fixture  for 

truing,  136. 

Cutter  grinding,  wheels  for,  305. 
Cutter  grinding,   wide  faced  wheels 

for,  294. 

Cutter  teeth  corners,  rounding,  300. 
Cutters,  angular,  grinding,  295. 
Cutters,  formed,  grinding,  302,  305. 
Cylinder  grinder,  adaptability  of,  261. 
Cylinder  grinder,  Heald,  255. 
Cylinder  grinding,  257. 
Cylinder  grinding,  wheels  for,  259. 
Cylindrical  grinding,  applications  of, 

238. 
Cylindrical   grinding,   how  to  order 

wheels  for,  144. 

Cylindrical  grinding,  machine  for  test- 
ing wheels  for,  119. 
Cylindrical  grinding  machines,  216. 
Cylindrical  grinding,  speed  for  wheel, 

223. 
Cylindrical  grinding,  testing  wheels 

for,  121. 

Cylindrical  grinding,  wheels  for,  235. 
Cylindrical     grinding     wheels,     star 

wheel  dresser  for  truing,  137. 


Data  for  wheel  test,  101. 

De  Beers  diamond  mines,  30. 

De-grades,  91. 

Demagnetizer,  Heald,  197. 

Demagnetizing  switch,  196. 

Deposits  of  Canadian  corundum,  21. 

Deposits  of  garnet,  33. 

Depth  of  cut,  224. 

Depth  of  cut  for  die  grinding,  192. 


Depth  of  finishing  cut  for  surface 
grinding,  199. 

Design  of  collars  for  dust  collecting 
system,  147. 

D.esign  of  elbows  for  dust  collecting 
system,  147. 

Designation  of  alundum  varieties,  58. 

Designation  of  wheel  grades,  91. 

Determining  grit  and  grade,  143. 

Development  of  artificial  corundum, 
48. 

Deville,  E.  H.,  Sainte-Claire,  53. 

Diamond,  13,  29. 

Diamond,  bort,  31. 

Diamond,  classes  of,  29. 

Diamond,  color  of,  31. 

Diamond  cutting,  introduction  of,  31. 

Diamond,  fracture  of,  29. 

Diamond,  hardness  of,  29. 

Diamond,  how  found,  30. 

Diamond,  how  mined,  30. 

Diamond,  how  to  use  for  truing  grind- 
ing wheel,  135. 

Diamond  mines,  De  Beers,  30. 

Diamond  powder,  how  prepared,  31. 

Diamond  powder,  uses  of,  31. 

Diamond,  preparing  for  market,  30. 

Diamond,  resetting  of,  135, 

Diamond,  specific  gravity  of,  29. 

Diamond  steel  emery,  64. 

Diamond,   wheel  truing,   setting  of, 

134- 

Diamond,  where  found,  29. 
Diamonds,  sorting,  31. 
Diamonds,   wheel   truing,   kinds   of, 

133- 

Die  grinding,  187. 
Die  grinding,  abrasives  used,  192. 
Die  grinding,  cross  feed  for,  192. 
Die,  grinding,  depth  of  cut,  192. 
Die  grinding  fixture,  190. 
Die  grinding,  wheels  for,    188,  192, 

199. 

Die  grinding  wheels,  truing,  19*3. 
Die,  sheared,  190. 
Dies,  locating  for  grinding,  188.. 
Dioscorides,  14. 

Discovery  of  American  emery,  16. 
Discovery  of  bauxite,  52. 
Discovery  of  Carborundum,  38. 
Discovery  of   Craigmont  corundum, 

24. 
Discs,  abrasive,  manufacture  of,  169. 


327 


INDEX 


Discs,  abrasive,  selection  of,  173. 

Discs,  abrasive,  testing,  1 74. 

Dog,  grinding,  221. 

Dollner's  artificial  alumina,  51. 

Double  tapers,  internal  grinding,  245. 

Dust  collecting  system,  branch  pipes, 
size  of,  146. 

Dust  collecting  system,  cleanouts  for, 
149. 

Dust  collecting  system,  design  of  col- 
lars for,  147. 

Dust  collecting  system,  design  of  el- 
bows for,  147. 

Dust  collecting  system,  location  of 
fan,  150. 

Dust  collecting  system,  main  pipes, 
148. 

Dresses,  emery  wheel  practicability 
of,  138. 

Dressing  grinding  wheel,  232. 

Dressing  grinding  wheels,  tools  used 
for,  133. 

Dull  milling  cutters,  results  of  using, 
290. 

Dunbar,  Howard  W.,  285. 

Dust  collecting  hood,  145. 

Dust  collecting  system,  location  of 
collector,  150. 

Dust  collecting  systems,  advantages 
of,  145. 

E 

Early  calender  rolls,  how  finished, 
265. 

Early  manufacture  of  abrasive  paper 
and  cloth,  167. 

Early  production  of  artificial  corun- 
dum, 47,  48. 

Early  uses  of  emery,  14. 

Earning  power  of   grinding   wheels, 

102. 

Ebelmen,  J.  J.,  48. 
Economical  use  of  wheels,  153. 
Economical  value  of  soft  wheels,  104. 
Effect  of  change  in  grade,  105. 
Effect  of  fine  grit  wheels  on  surface 

grinding,  200. 
Effect  of  vibration,  131. 
Effect  of  wheel  speed  on  grade,  95. 
Efficiency  of  grindstones,  125. 
Efficiency  of  large  grinding  wheels, 

131- 
Efficiency  test,  ideal  casting  for,  101. 


Elastic  process,  80. 

Elastic  wheels,  purposes  used  for,  80. 

Elbows  for  dust  collecting  system,  de- 
sign of,  147. 

Electric  furnace,  Hasslacher's,  49. 

Electric  furnace,  Jacobs',  54. 

Electrolon,  47. 

Electrolon,  how  made,  47. 

Emery,  14. 

Emery  characteristics  of,  17. 

Emery  cloth,  168. 

Emery,  color  of,  15. 

Emery,  diamond  steel,  64. 

Emery,  early  uses  of,  14. 

Emery,  how  found,  15. 

Emery,  how  mined,  15. 

Emery,  impurities  of,  17. 

Emery,  Naxos,  16. 

Emery  paper,  168. 

Emery,  percentage  of  alumina,  17. 

Emery,  specific  gravity  of,  17. 

Emery,  spinel,  16. 

Emery,  spinel,  component  parts  of, 
16. 

Emery,  spinel,  hardness  of,  16. 

Emery  stones,  19. 

Emery,  Turkish,  15. 

Emery,  uses  of,  19. 

Emery  wheel  dressers,  practicability 
of,  138. 

Emery,  where  found,  14.    ' 

End  mills,  grinding,  302. 


Face  grinding,  240. 

Face  grinding  machine,  180. 

Face  of  wheel,  grinding  with,  238. 

Facing  and  edging  grinding  wheels,74. 

Facing  gear  case  covers,  184,  185. 

Facing  grinding  wheels,  tools  used,  74. 

Factors  for  laboratory  tests,  116. 

Factors  to  consider  in  selecting  grind- 
ing wheels,  129. 

Fallacy  of  medium  grade,  92. 

Fan,  location  of  in  dust  collecting 
system,  150. 

Farrel  roll  crowning  mechanism,  268. 

Farrel  roll  grinder,  266. 

Feed,  cross,  for  die  grinding,  192. 

Feed  traverse,  224. 

Feed,  traverse,  for  roll  grinding,  273. 

Feil,  C,  48. 


328 


INDEX 


Ferro  silicon,  59. 
Filing  room,  312. 
Fine  grit  wheels,  effect  of  on  surface 

grinding,  200. 
Finish  allowance  in  cylinder  grinding, 

257- 
Finishing    Carborundum    sharpening 

stones,  86. 

Finishing  chip,  allowance  for,  223. 
Finishing  crank  cases,  185. 
Finishing  cut,   depth  of  for  surface 

grinding,  199. 

Firing  a  grinding  wheel  kiln,  71. 
Fixture  for  holding  punches,  192. 
Fixture  for  truing  cutter  grinding 

wheels,  136. 

Fixture  for  die  grinding,  190. 
Fixture  for  truing   surface   grinding 

wheels,  136. 

Fixture,  grinding,  rotary,  183. 
Flanges,  safety,  154. 
Flanges,  wheel,  plain,  danger  of,  153. 
Flanges,  wheel,  proportion  of,  153. 
Flint,  composition  of,  34. 
Flint,  fracture  of,  34. 
Flint  quartz,  uses  of,  35. 
Flint  quartz,  where  found,  35. 
Flint,  specific  gravity  of,  34. 
Formation  of  Tripoli,  36. 
Formed  cutter  grinding  attachment, 

Brown  &  Sharpe,  304. 
Formed  cutters,  grinding,  302,  305. 
Fourgrinder,  Henry,  263. 
Fracture  of  carbonado,  32. 
Fracture  of  Carborundum,  41. 
Fracture  of  diamond,  29. 
Fracture  of  flint,  34. 
Fracture  of  quartz,  34. 
Fremy,  E.,  48. 
Full  heat  of  kiln,  73. 
Furnace,  Aloxite,  58. 
Furnace,  Carborundum,  38. 
Furnace,   Carborundum,   by-product 

of,  40. 
Furnace,  Carborundum,  contents  of, 

40. 
Furnace,  Carborundum,  heat  of,  40. 


Garnet,  32. 

Garnet,  hardness  of,  33. 

Garnet,  how  crystallized,  32. 


Garnet,  how  found,  33. 
Garnet,  how  prepared,  33. 
Garnet,  impurities  of,  171. 
Garnet,  kinds  of,  32. 
Garnet  paper  belts,  testing,  172. 
Garnet  paper,  kinds  of,  168. 
Garnet  paper,  testing,  170. 
Garnet,  specific  gravity  of,  33. 
Garnet,  testing,  171. 
Garnet,  uses  of,  33. 
Garnet,  where  found,  33. 
Gaudin,  M.  A.  A.,  48. 
Gear  case  covers,  facing,  184,  185. 
Gear  chucks,  248,  251,  252,  253. 
Gears,  grinding  holes  in,  248. 
German    artificial    corundum,    how 

made,  49. 

German  carbide  of  silicon,  46. 
Grade  blocks,  master,  91. 
Grade,  change  in,  effect  of,  105. 
Grade  list,  reliable,  how  compiled,  92. 
Grade  lists,  comparative,  inaccuracy 

of,  91. 

Grade,  running,  96. 
Grade  scale,  reliability  of,  94. 
Grade  scale,  universal,  93,  94. 
Grades  of  grinding  wheels,  91. 
Grades,  wheel,  how  designated,  91. 
Grading  Carborundum,  43. 
Grading  Carborundum  powder,  44. 
Grinder,  cylindrical,  preparing  work 

for,  220. 

Grinder,  plain  cylindrical,  217. 
Grinder,  roll,  Parrel,  266. 
Grinder,  setting  straight,  222. 
Grinder,   surface,   Brown  &  Sharpe, 

1 88. 
Grinder,  surface,  Pratt  &  Whitney, 

203. 

Grinder,  universal,  217. 
Grinding  allowance  for  cylinders,  257. 
Grinding  allowances,  220. 
Grinding  a  taper,  238,  240. 
Grinding  axes,  125. 
Grinding  calender  rolls,  269. 
Grinding  centers,  240. 
Grinding  chain  links,  1 1 2. 
Grinding  chilled  car  wheels,  106. 
Grinding  crankshafts,  277. 
Grinding  cylinders,  257. 
Grinding,  cylindrical,  applications  of, 

238. 
Grinding,  cylindrical,  wheels  for,  235. 


329 


INDEX 


Grinding  dies,  187. 

Grinding  dog,  221. 

Grinding,  face,  240. 

Grinding  fixture,  rotary,  183. 

Grinding  holes  in  gears,  248. 

Grinding,  internal,  243. 

Grinding  internal  tapers,  245. 

Grinding  links,  288. 

Grinding     locomotive     guide     bars, 

marks,  181. 

Grinding  lubricant,  210,  231. 
Grinding  machine,  face,  180. 
Grinding  machine,  surface,  wet,  193. 
Grinding  machines,  cylindrical,  216. 
Grinding  machines,  internal,  types  of, 

245- 

Grinding  machines,  modern,  218. 
Grinding  machines,  saw,  309. 
Grinding  metal  cutting  saws,  315,  319. 
Grinding  milling  cutters,  292. 
Grinding  pearl  buttons,  114. 
Grinding  plow  points,  105. 
Grinding  punches,  191. 
Grinding  saws,  310. 
Grinding  sides  of  milling  cutters,  243. 
Grinding  size  blocks,  176. 
Grinding,  spot,  176. 
Grinding   steel   with    Carborundum, 

45- 

Grinding  wheel  bond,  66. 

Grinding  wheel  bonds,  how  standard- 
ized, 67. 

Grinding  wheel  bonds,  varieties  of,  67. 

Grinding  wheel,  dressing,  232. 

Grinding  wheel,  early  development  of, 
123. 

Grinding  wheel,  efficiency  value  of, 
1 06. 

Grinding  wheel,  future  of,  in  axe  in- 
dustry, 127. 

Grinding  wheel  grades,  91. 

Grinding  wheel  grits,  88. 

Grinding  wheel,  how  to  true  with  dia- 
mond, 135. 

Grinding  wheel  kiln,  firing,  71. 

Grinding   wheel   materials,   methods 

-     used  in  mixing,  68. 

Grinding  wheel  press,  68. 

Grinding  wheel,  rebushing,  141. 

Grinding  wheel  sagers,  71. 

Grinding  wheel  speeds,  96. 

Grinding  wheel,  surface,  guards  for, 
159- 


Grinding  wheel,  surface,  sizing  power 

of,  199. 

Grinding  wheel,  truing,  232. 
Grinding  wheel  volume,  how  to  find, 

io7. 
Grinding  wheels,  advantages  of,  in 

axe  grinding,  126. 
Grinding  wheels,  balancing,  76. 
Grinding  wheels,  causes  of  breakage, 

151. 

Grinding  wheels,  comparative  val- 
ues of,  129. 

Grinding  wheels,  composition  of,  65. 
Grinding  wheels,  cutter,  fixture  for 

truing,  136. 

Grinding  wheels,  earning  power,  102. 
Grinding  wheels,  economical  use  of, 

153- 
Grinding  wheels,  facing*  and  edging, 

74- 

Grinding  wheels,  factors  to  consider 
in  selecting,  129. 

Grinding  wheels  and  grindstones, 
comparative  costs  of,  126. 

Grinding  wheels,  hardness,  how  con- 
trolled, 67. 

Grinding  wheels,  how  bushed,  75. 

Grinding  wheels,  inspecting  for  grade, 

74- 
Grinding  wheels,   large,   advantages 

of  using,  130. 
Grinding  wheels,  large,  efficiency  of, 

131-- 

Grinding  wheels,  mounting,  153. 

Grinding  wheels,  operating  speed, 
how  designated,  152. 

Grinding  wheels,  ordering,  informa- 
tion to  give,  142. 

Grinding  wheels,  reasons  for  over- 
speeding,  152. 

Grinding  wheels,  re-bushing,  advan- 
tages of,  139. 

Grinding  wheels,  re-bushing  tools 
used  for,  139. 

Grinding  wheels,  selection  of,  97. 

Grinding  wheels,  shaving,  69. 

Grinding  wheels,  small,  why  used,  132. 

Grinding  wheels,  sorting,  73. 

Grinding  wheels,  special  how  to  order, 
144. 

Grinding  wheels,  speed  testing,  76. 

Grinding  wheels,  surface,  fixture  for 
truing,  136.  . 


330 


INDEX 


Grinding  wheels,  tamping,  79. 
Grinding  wheels,  testing  for  sound- 
ness, 74. 
Grinding    wheels,    tests,    laboratory. 

US- 

Grinding  wheels,  three  methods  of 
testing,  114. 

Grinding  wheels,  tools  used  for  dress- 
ing. *  33- 

Grinding  wheels,  wire  web,  124. 

Grinding  wheels,  wire  web,  80. 

Grinding  with  face  of  wheel,  238. 

Grindstone  action,  124. 

Grindstone,  efficiency  of,  125. 

Grindstone,  life  of,  125. 

Grindstone,  uses  of,  125. 

Grindstones  and  grinding  wheels,  cost 
comparisons,  126. 

Grindstones,  characteristics  of,   127. 

Grindstones,  uses  of,  14. 

Grit  and  grade,  how  determined,  143. 

Grit  and  grade  of  wheels  for  spot 
grinding,  178. 

Grit,  angular,  64. 

Grits,  combination,  89.      , 

Grits  of  abrasive  paper  and  cloth,  89. 

Grits  of  Carborundum  sharpening 
stones,  85. 

Grits,  grinding  wheel,  88. 

Grits,  mixed,  88. 

Grits,  straight,  88. 

Guard,  pulley,  162. 

Guard,  spindle,   161. 

Guard,  wheel,  247. 

Guarded  surface  grinding  wheels,  159. 

Guards,  wheel,  156. 

Guards,  wheel,  unsafe,  164. 

Guide  bar,  locomotive,  grinding,  181. 

Guide  bars,  locomotive,  lapping,  170. 

Guide  bars,  locomotive,  wear  on,  181. 

Guide  finger,  locating,  294. 


H 


Hack  saw  blade  grinder,  Ward  well, 

3I9- 

Hack  saw  blades,  grinding,  321. 
Hammett  link  grinder,  287. 
Hard  and  soft  spots,  how  caused,  72. 
Hard  or  soft  wheels,  how  to  rectify,  95. 
Hard  or  soft  wheels,  how  to  remedy, 

144. 
Hardness  of  Carborundum,  41. 


Hardness  of  corundum,  22. 
Hardness  of  diamonds,  29. 
Hardness  of  garnet,  33. 
Hardness   of   grinding    wheels,    how 

controlled,  7. 
Hardness  of  quartz,  34. 
Hardness  of  spinel  emery,  16. 
Hasslacher's  electric  furnace,  49. 
Hasslacher,  Franz,  49. 
Haultain,  H.  E.  T.,  21,  24. 
Head,  universal,  299. 
Heald  bushing  chuck,  248. 
Heald  cylinder  grinder,  255. 
Heald  demagnetizer,  197. 
Heald  internal  grinder,  246. 
Heald  magnetic  chuck,  194. 
Heald  ring  grinder,  200. 
Heald  rotary  surface  grinder,  202. 
Heat  of  Carborundum  furnace,  40. 
Holes  in  gears,  grinding,  248. 
Hollinger,  J.  H.,  108. 
Hone,  razor,  Belgian,  35. 
Hood,  dust  collecting,  145. 
Horsepower  required  to  operate  Alun- 

dum  furnace,  57. 


Ideal  casting  for  efficiency  test,  101. 

Ideal  corundum,  22. 

Impurities  of  Carborundum,  42. 

Impurities  of  emery,  17. 

Impurities  of  garnet,  171. 

Impurities  of  pumice,  36. 

Impurities  of  sandstone,  14. 

Inaccuracy,  causes  of,  in  roll  winding, 
272. 

Inaccuracy  of  comparative  grade  lists, 
91. 

Information  to  give  in  ordering  grind- 
ing wheels,  142. 

Ingot,  Aloxite,  59. 

Inspecting  grinding  wheels  for  grade, 

74- 

Internal  grinder,  Heald,  246. 
Internal  grinding,  243. 
Internal  grinding,  allowance  for,  253. 
Internal  grinding,  chucking  work  for, 

247. 
Internal  grinding  machines,  types  of, 

245- 

Internal  grinding,  setting  up  univer- 
sal grinder  for,  243. 


331 


INDEX 


Internal  grinding,  wheel  speeds  for, 

254- 

Internal  grinding  wheels,  truing,  255. 
Internal  tapers,  grinding,  245. 
Introduction  of  diamond  cutting,  31. 


Jacobs,  Charles  B.,  53. 
Jacobs'  electric  furnace,  54. 
Jacobs  process  for  making  artificial 
corundum,  56. 


K 


Kiln,  full  heat  of,  73. 

Kiln  grinding  wheel  firing,  71. 

Kiln,  low  melting  point  of,  72. 

Kiln,  red  heat  of,  72. 

Kiln,  testing  heat  of,  72. 

Kiln,  vitrifying,  70. 

Kinds  of  backrests,  226. 

Kinds  of  garnet,  32. 

Kinds  of  wheel  truing  diamonds,  133. 


Laboratory  grinding  wheel  tests,  115. 
Laboratory  test  on  wheels  for  rough 

grinding    operations,  how   carried 

out,  1 1 8. 

Laboratory  tests,  factors  for,  115. 
Landis  balancing  device,  235. 
Landis  crankshaft  grinder,  275. 
Landis  mill  roll  grinder,  270. 
Landis  plain  grinder,  217. 
Lapping  locomotive  guide  bars,  170. 
Large  cutters,  sharpening,  299. 
Large  grinding  wheels,  advantages  of 

using,  130. 
Large  grinding  wheels,  efficiency  of, 

131- 

Leaders  for  cam  grinder,  283. 
Leaders  for  cam  grinding,  how  made, 

284. 

Life  of  grindstone,  125. 
Limits  in  using  soft  wheels,  104. 
Link  grinder,  Hammett,  287. 
Link  grinding,  288. 
Link  grinding,  wheels  for,  289. 
Links,  valve  gear,  types  of,  286. 
Loading  grinding  wheel  sagers,  71. 
Locating  cutters  for  grinding,  291. 


Locating  dies  for  grinding,  188. 
Locating  guide  finger,  294. 
Locating  mill  rolls  for  grinding,  272. 
Locating  work  on  Blanchard  grinder, 

211. 

Location  of  Arkansas  sharpening 
stone  deposits,  35. 

Location  of  bauxite  deposits,  53,  54. 

Location  of  carbonado  deposits,  32. 

Location  of  corundum  deposits,  21, 
25,26. 

Location  of  diamond  deposits,  29. 

Location  of  emery  deposits,  15. 

Location  of  flint  quartz  deposits, 
35- 

Location  of  Tripoli  deposits,  36. 

Locomotive  guide  bar  grinding,  181. 

Locomotive  guide  bar  grinding,  test- 
ing wheels  for,  no. 

Locomotive  guide  bars,  lapping,  171. 

Locomotive  guide  bars,  wear  on,  181. 

Loose  spindles,  156. 

Low  melting  point  of  kiln,  72. 

Lubricant,  grinding,  210,  231. 

Lubrication  of  spindle,  255,  258. 

Lucas,  Dr.  H.  S.,  16. 


M 


Machine,  coating,  for  making  abra- 
sive paper  and  cloth,  167. 

Machine  for  testing  wheels  used  on 
cylindrical  grinding,   119. 

Machine  for  testing  wheels  used  for 
rough  operations,  116. 

Machine,  shaving,  69. 

Machines  used  for  cutter  grinding, 
290. 

Magnetic  chuck,  Heald,  194. 

Magnetic  chuck,  taper,  194. 

Magnetic  chuck,  swivel,  194. 

Magnetic  chucks,  current  for,  197. 

Manufacture  of  abrasive  discs,  169. 

Manufacture  of  Alundum,  57. 

Manufacture  of  Crystolon,  47. 

Manufacture  of  Electrolon,  47. 

Manufacture  of  German  artificial  cor- 
undum, 49. 

Marks,  chatter,  cause  of,  232. 

Master  grade  blocks,  91. 
'Materials,  bonding,  66. 

Materials,  raw,  Carborundum,  38. 

Materials  used  on  abrasive  discs,  173. 


332 


INDEX 


Matteson  saw  grinder,  315. 
Medium  grade,  fallacy  of,  92. 
Metal  cutting  saws,  315. 
Metal   cutting   saws,   grinding,    315, 

319. 

Methods   of   mixing   grinding   wheel 

materials,  68. 

Mill  roll  grinder,  Landis,  270. 
Mill  roll  grinder,  Norton,  271. 
Mill  rolls,  locating  fcr  grinding,  272. 
Milling  cutters,  dull,  results  of  using, 

290. 

Milling  cutters,  grinding,  292. 
Milling  cutters,  grinding  sides  of,  242. 
Milling  cutters,  re-cutting,  306. 
Mills,  end,  grinding,  302. 
Mineral,  Spanish,  33. 
Mining  of  diamonds,  30. 
Mining  of  emery,  15. 
Mixed  grits,  88. 
Mixing    grinding    wheel    materials, 

methods  used,  68. 
Modern  grinding  machines,  218. 
Molding    Carborundum    sharpening 

stones,  84. 
Mounting  grinding  wheels,  153. 


X 


Natural  abrasives,  13. 
Natural  sharpening  stones,  35. 
Naxos  emery,  16. 
Newton  saw  grinder,  316. 
Norton  backrest,  setting,  226. 
Norton  cam  grinding  attachment,  280. 
Norton  mill  roll  grinder,  271. 
Norton  plain  grinder,  219. 
Norton  solid  backrest,  226. 
Numbers  of  Carborundum  grain,  44. 


Operating  speed  of  grinding  wheels, 
how  designated,  152. 

Operation  of  Blanchard  grinder,  212. 

Ordering  grinding  wheels,  informa- 
tion to  give,  142. 

Ordering  special  grinding  wheels,  144. 

Ordering  wheels  for  cylindrical  grind- 
ing, 144. 

Oriental  ruby,  47. 

Origin  of  name  of  bauxite,  53. 

Origin  of  pumice,  36. 


Overspeeding  of  grinding  wheels,  rea- 
sons for,  152. 
Oxalumina,  63. 

Oxalumina,  composition  of,  63. 
Oxalumina,  how  made,  63. 
Oxalumina,  uses  of,  63. 


Paper  and  cloth,  abrasive,  early  man- 
ufacture of,  167. 
Paper  and  cloth,  abrasive,  uses  of, 

1 66. 

Paper,  Carborundum,  168. 
Paper,  emery,  168. 
Paper,  garnet,  kinds  of,  168. 
Paper,  garnet,  testing,  170. 
Paper,  sand,  169. 
Pearl  button  grinding,  114. 
Peripheral   speed,   effect   on   surface 

grinding,  199. 
Pigs,  Alundum,  57. 
Plain  cylindrical  grinder,  217. 
Plain  grinder,  Landis,  217. 
Plain  grinder,  Norton,  219. 
Plain  grinding  wheel  flanges,  danger 

of,  153- 
Pliny,  14. 

Plow  points,  grinding,  105. 
Pointing  up  saws,  310. 
Power   required   to   operate  Aloxite 

furnace,  58. 

Pratt  &  Whitney  surface  grinder,  203. 
Pratt    &    Whitney    surface    grinder, 

samples  of  work  done  on,  206. 
Pratt,  Prof.  J.  H.,  20,  21. 
Preparation  of  Aloxite  grain,  59. 
Preparation  of  corundum,  24. 
Preparation  of  diamond  powder,  31. 
Preparation  of  garnet,  33. 
Preparation  of  work  for  cylindrical 

grinder,  220. 

Preparing  diamonds  for  market,  30. 
Press,  grinding  wheel,  68. 
Pressed  process,  68. 
Pressed  wheels,  characteristics  of,  68. 
Process  for  making  Jacobs'  artificial 

corundum,  56. 

Process  of  making  Aloxite,  58. 
Process  of  making  Alundum,  57. 
Process  of  making  Carborundum,  39. 
Process  of  making  crushed  steel,  63. 
Process  of  making  Oxalumina,  63. 


333 


INDEX 


Process,  elastic,  80. 

Process,  pressed,  68. 

Process,  puddled,  69. 

Process,  rubber,  81. 

Process,  silicate,  79. 

Process,  vitrified,  67. 

Proportion  of  wheel  flanges,  153. 

Puddled  process,  69. 

Pulley  guard,  162. 

Pulp  stones,  125. 

Pumice,  impurities  of,  36. 

Pumice,  origin  of,  36. 

Pumice  stone,  36. 

Pumice,  uses  of,  36. 

Punches,  fixture  for  holding,  192. 

Punches,  grinding,  191. 

Purifying  Carborundum,  42. 

Purity  of  Aloxite,  59. 

Pyrometric  cones,  72. 


Quartz,  34. 

Quartz,  composition  .of ,  34. 
Quartz,  flint,  where  found,  35. 
Quartz,  fracture  of,  34. 
Quartz,  hardness  of,  34. 
Quartz,  how  crystallized,  34. 
Quartz,  specific  gravity  of,  34. 
Quartz,  uses  of,  34'. 


Radius  truing  device  for  crankshaft 
grinder,  277. 

Rapid  wheel  wear,  104. 

Raw  materials,  Carborundum,  38. 

Razor  hone,  Belgian,  35. 

Razor  hones,  Carborundum,  85. 

Re-bushing  grinding  wheels,  141. 

Re-bushing  grinding  wheels,  advan- 
tages of,  139. 

Re-bushing  grinding  wheels,  tools 
used  for,  139. 

Records  of  tests,  how  to  keep,  119. 

Rectifying  hard  or  soft  wheels,  95. 

Re-cutting  milling  cutters,  306. 

Red  heat  of  kiln,  72. 

Reliability  of  grade  scale,  94. 

Reliable  grade  list,  how  compiled,  92. 

Remedying  hard  or  soft  wheels,  144. 

Re-saws,  band,  309. 

Re-saws,  band,  grinding,  314. 


Resetting  diamonds,  135. 

Rest,  work,  154. 

Rest,  work,  cause  of  accidents,  155. 

Ring  grinder,  Heald,  200. 

Ring  wheel  chuck,  1 80. 

Robert,  Louis,  265. 

Roll    crowning    mechanism,    Parrel, 

268. 

Roll  crowning,  reason  for,  267. 
Roll  grinder,  Parrel,  266. 
Roll  grinding,  causes  of  inaccuracy, 

272. 

Roll  grinding,  testing  wheels,  on,  108. 
Roll  grinding,  traverse  feed  for,  273. 
Roll  grinding,  wheel  speed,  273. 
Roll  grinding,  wheel  speed  for,  269. 
Roll  grinding,  wheels  for,  268. 
Roll  grinding,  work  speed  for,  273. 
Rolls,  calender,  causes  of  wear  of,  264. 
Rolls,  calender,  early,  how  finished, 

265. 

Rolls,  calender,  grinding,  269. 
Rolls,  calender,  largest  stack  of,  263. 
Rolls,  calender,  old  installation,  26. 
Rolls  for  steel  mills,  270. 
Rolls,  flour  mill,  grinding,  273. 
Rolls,  flour  mill,  wheels  for  grinding, 

274. 

Rolls,  mill,  locating  for  grinding,  272. 
Rolls,  steel  mill,  grinding,  272. 
Room,  filing,  312. 
Rotary  chucks  for  surface  grinder, 

204. 

Rotary  grinding  fixture,  183. 
Rotary  surface  grinder,  Heald,  202. 
Rotten  stone,  36. 
Rouge,  63.      . 
Rough  grinding  operations,  machine 

used  for  testing  wheels  for,  116. 
Rough   grinding   operations,    testing 

wheels  for,  118. 
Roughing  out  saws,  310. 
Rounding  cutter  teeth  corners,  300. 
Rubber  process,  81. 
Rubs,  Carborundum,  86. 
Ruby,  balas,  47. 
Ruby,  composition  of,  48. 
Ruby,  Oriental,  47. 
Ruby,  spinel,  47. 
Ruby,  value  of,  47. 
Running  grade,  96. 
Rule  for  finding  wheel  speed,  224. 
Rushing  chuck,  Heald,  248. 


334 


INDEX 


S 


Safety  flanges,  154. 

Sagers,  grinding  wheel,  71. 

Sagers,  how  loaded,  71. 

Samples  of  work  done  on  Blanchard 

surface  grinder,  210. 
Samples  of  work  done  on  Pratt  & 

Whitney  surface  grinder,  206. 
Sand-paper,  169. 
Sandstone,  13. 
Sandstone,  colors  of,  14. 
Sandstone,  impurities  of,  14. 
Sandstone,  where  found,  14. 
Saw  grinder,  Matteson,  315. 
Saw  grinder,  Newton,  316. 
Saw  grinding,  effect  of  speed  in,~3I2. 
Saw  grinding  machines,  309. 
Saw  grinding  machines,  care  of,  312. 
Saw  grinding  wheels,  shapes  of,  313. 
Saw  grinding,  wheels  used  for,  313. 
Saws,  band,  308. 

Saws,  case  hardening,  causes  of,  313. 
Saws,  circular,  308. 
Saws,  grinding,  310. 
Saws,  hack,  grinding,  321. 
Saws,  metal  cutting,  315. 
Saws,  metal  cutting,  grinding,  315, 

319. 

Saws,  pointing  up,  310. 
Saws,  roughing  out,  310. 
Saws,  wood-working,  types  of,  308. 
Scythe  stones,  36. 
Selecting  grinding  wheels,  factors  to 

consider,  129. 

Selection  of  abrasive  discs,  173. 
Selection  of  grinding  wheels,  97. 
Selection  of  wheels  for  surfacing,  187. 
Semi-automatic  grinding  operations, 

testing  wheels  for,  in. 
Setting  grinders  straight,  222. 
Setting  wheel  truing  diamond,  134. 
Shafting,  testing  wheels  for  grinding, 

109. 

Shape  of  Carborundum  crystals,  41. 
Shapes  of  saw  grinding  wheels,  313. 
Sharpening  large  cutters,  299. 
Sharpening  stories,  Arkansas,  35. 
Sharpening  stones,  artificial,  83. 
Sharpening  stones,  Carborundum,  83. 
Sharpening     stones,     Carborundum, 

how  finished,  86. 
Sharpening  stones,  natural,  35. 


Sharpening  stones,  Turkey,  35. 

Shaving  machine,  69. 

Sheared  die,  190. 

Side  surfacer,  180. 

Side  surfacer,  varieties  of  work 
ground  on,  182. 

Side  teeth,  grinding,  297,  298. 

Silicate  bonded  wheels,  purposes  used 
for,  79. 

Silicate  process,"  79. 

Silicon  carbide,  38. 

Silicon,  ferro,  59. 

Size  blocks,  grinding,  176. 

Size  of  branch  pipes  for  dust  collect- 
ing system,  146.  ,  / 

Sizes  and  numbers  of  abrasive  paper 
and  cloth,  168. 

Sizes  of  angular  grit,  64. 

Sizes  of  crushed  steel,  64. 

Sizing  power  of  surface  grinding 
•  wheel,  199. 

Sleeve  for  cutter  grinding,  293. 

Small  grinding  wheels,  why  used,  132. 

Smith,  Dr.  J.  Lawrence,  15. 

Soft  wheels,  economical  value  of,  104. 

Soft  wheels,  limits  in  using,  104. 

Solid  backrest,  Norton,  226. 

Sorting  diamonds,  31. 

Sorting  grinding  wheels,  73. 

Spanish  mineral,  33. 

Sparking,  uneven,  225. 

Special  wheels,  how  to  order,  144. 

Specific  gravity  of  carbonado,  29 

Specific  gravity  of  Carborundum,  41. 

Specific  gravity  of  diamond,  29. 

Specific  gravity  of  emery,  17. 

Specific  gravity  of  flint,  34. 

Specific  gravity  of  garnet,  33. 

Specific  gravity  of  quartz,  34. 

Speed,  effect  of,  in  saw  grinding,  312. 

Speed  of  wheel  for  cylindrical  grind- 
ing, 223. 

Speed  of  wheel,  rule  for  finding,  224. 

Speed,  table  for  surfacing,  187. 

Speed  testing  grinding  wheels,  76. 

Speed,  work,  223. 

Speed,  work,  for  roll  grinding,  269. 

Speeds  for  surface  grinding,  185. 

Speeds  of  grinding  wheels,  96. 

Spindle  guard,  161. 

Spindles,  loose,  156. 

Spinel,  emery,  16. 

Spinel,  emery,  component  parts  of,  16. 


335 


INDEX 


Spinel,  emery,  hardness  of,  16. 

Spinel,  ruby,  47. 

Spot  grinding,  176. 

Spot  grinding  wheels,  grit  and  grade 

of,  178. 

Square  center,  221. 
Standardization    of    grinding    wheel 

bonds,  67. 

Standardized  wheel  grades,  94. 
Star  wheel  dresser  for  truing  cylin- 
drical grinding  wheels,  137. 
Steady-rests  for  cam  grinding,  282. 
Steel  grinding  with  Carborundum,  45. 
Steel  mill  rolls,  270. 
Steel  mill  rolls,  grinding,  272. 
Stone,  pumice,  36. 
Stone,  rotten,  36. 
Stones,  emery,  19. 
Stones,  pulp,   125. 
Stones,  scythe,  36. 
Stones,  sharpening,  natural,  35. 
Stones,  sharpening,  Turkey,  35. 
Straight  grits,  88. 

Surface  grinder,  Brown  &  Sharpe,  188. 
Surface  grinder,   Pratt  &  Whitney, 

203. 
Surface  grinder,   Pratt  &  Whitney, 

selection  of  wheels  for,  206. 
Surface  grinder,  rotary,  Heald,  202. 
Surface  grinders,  comparison  of,  202. 
Surface  grinding,  adapting  wheel  for, 

199. 

Surface  grinding  chucks,  rotary,  204. 
Surface  grinding,  depth  of  finishing 

cut,  199. 
Surface  grinding,  effect  of  fine  grit 

wheels,  200. 
Surface  grinding,  effect  of  peripheral 

speed  on,  199. 
Surface  grinding  machine,  Blanchard, 

208. 

Surface  grinding  machine,  wet,  193. 
Surface  grinding,  speeds  for,  185. 
Surface  grinding  wheel  guards,  159. 
Surface  grinding  wheel,  sizing  power 

of,  199. 
Surface  grinding  wheels,  fixture  for 

truing,  136. 
Surfacer,  side,  180. 
Surfacer,    side,    varieties    of   work, 

ground  on,   182. 

Surfacing,  selection  of  wheels  for,  187. 
Surfacing,  table  speed  for,  187. 


Switch,  demagnetizing,  196. 
Swivel  magnetic  chuck,  194. 
System,  dust  collecting,  main  pipes 

for,  148. 
Systems,  dust  collecting,  advantages 

of,  145. 


Table  speed  for  surfacing,  187. 

Tamping  grinding  wheels,  79. 

Taper  grinding,  238,  240. 

Taper  magnetic  chuck,  194. 

Tapers,  grinding  double  internal,  245. 

Teeth,  side  grinding,  297,  298. 

Temper,  abrasive,  52. 

Temper  of  artificial  corundum,  56. 

Test  records,  how  to  keep,  119. 

Test  wheel  data,  101. 

Testing  abrasive  discs,  174. 

Testing  bonding  materials,  67. 

Testing  corundum,  25. 

Testing  garnet,  171. 

Testing  garnet  paper,  170. 

Testing  garnet  paper  belts,  172. 

Testing  grinding  wheels  for  sound- 
ness, 74. 

Testing  grinding  wheels  in  the  lab- 
oratory, 115. 

Testing  heat  of  kiln,  72. 

Testing  operation,  truing  wheel  in, 
118. 

Testing  trial  wheels,  wrong  method, 
98. 

Testing  wheels  for  car  wheel  grinding, 
106. 

Testing  wheels  for  cylindrical  grind- 
ing, 121. 

Testing  wheels  for  grinding  shafting, 
109. 

Testing  wheels  for  locomotive  guide 
bar  grinding,  no. 

Testing  wheels  for  semi-automatic 
grinding  operations,  in. 

Testing  wheels  on  chilled  iron  roll 
grinding,  108. 

Three  methods  of  testing  grinding 
wheels,  114. 

Tight  wheel  bushings  as  cause  of 
accidents,  153. 

Time  consumed  in  axe  grinding,  126. 

Time  necessary  to  vitrify  wheels,  73. 

Tools  used  for  dressing  grinding 
wheels,  133. 


336 


INDEX 


Tools  used  for  facing  grinding  wheels, 

74- 
Tools  used  for  re-bushing  grinding 

wheels,  139. 
Traverse  feed,  224. 

Traverse  feed  for  roll  grinding,  273. 
Trial  wheels,  correct  method  of  test- 
ing, IOO. 
Trial  wheels,  wrong  method  of  testing, 

98. 

Tripoli,  36. 

Tripoli,  how  formed,  36. 
Tripoli,  uses  of,  36. 
Tripoli,  where  found,  36. 
Truing    cylindrical    grinding    wheels 

with  star  wheel  dresser,  137. 
Truing  die  grinding  wheels,  192. 
Truing  grinding  wheel,  232. 
Truing  internal  grinding  wheels,  255, 

258. 
Truing   wheel  in   testing   operation, 

118. 
Truing    wheels   on    vertical    spindle 

grinder,  138. 

Turkey  sharpening  stones,  35. 
Turkish  emery,   15. 


U 


Uneven  sparking,  225. 

Unguarded  wheels,   157. 

Universal  Brown  &  Sharpe  backrest, 
228. 

Universal  grade  scale,  93,  94. 

Universal  grinder,  217. 

Universal  grinder,  Brown  &  Sharpe, 
236. 

Universal  grinder,  setting  up  for  inter- 
nal grinding,  243. 

Universal  head,  299. 

Unsafe  wheel  guards,  164. 

Uses  of  abrasive  paper  and  cloth,  166. 

Uses' of  Aloxite,  60. 

Uses  of  Alundum,  58. 

Uses  of  angular  grit,  64. 

Uses  of  Arkansas  sharpening  stones, 
35- 

Uses  of  Boro-Carbone,  62. 

Uses  of  carbonado,  32. 

Uses  of  Carborundum,  45. 

Uses  of  Corubin,  52. 

Uses  of  corundum,  29. 

Uses  of  crushed  steel,  64. 


Uses  of  diamond  powder,  3lc 

Uses  of  emery,  19. 

Uses  of  flint  quartz,  35. 

Uses  of  garnet,  33. 

Uses  of  grindstones,  14,  125. 

Uses  of  Oxalumina,  63. 

Uses  of  pumice,  36. 

Uses  of  quartz,  34. 

Uses  of  Tripoli,  36. 


Value   of  grinding   wheel  efficiency,1 

106. 

Value  of  ruby,  47. 
Valve  gear  links,  types  of,  286. 
Varieties  of  Alundum,  58. 
Varieties    of    Arkansas     sharpening 

stones,  35. 

Varieties  of  corundum,  21. 
Varieties  of  grinding  wheel  bonds,  67. 
Varieties  of  work  finished  on  side  sur- 

facer,  182. 
Vertical      spindle      grinder,      truing 

wheels  on,   138. 
Vertical    surface    grinder,    Pratt    & 

Whitney,  selection  of  wheels  for, 

206. 

Vibration,  effect  of,  131. 
Vitrified  process,  67. 
Vitrifying  kiln,  70. 
Vitrifying  process,  time  consumed  to 

carry  out,  73. 

Voltage  of  Carborundum  furnace,  40. 
Volume   of   grinding   wheel,  how  to 

find,  107. 
von  Berquen,  L.,  31. 

W 

Walker  cutter  grinder,  299. 

Ward  well  hack  sawblade  grinder,  319. 

Wear  on  locomotive  guide  bars,  181. 

Werlein's  artificial  abrasive,  61. 

Wet  surface  grinding  machine,  193. 

Wheel  balance,  234. 

Wheel  chattering,  200. 

Wheel  flanges,  proportion  of,  153. 

Wheel  grades,  how  designated,  91. 

Wheel  grades,  standardization  of,  94. 

Wheel  guard,  247. 

Wheel  guards,   156. 

Wheel  guards,  unsafe,  164. 


337 


INDEX 


Wheel  speed,  effect  on  grade,  95. 
Wheel  speed  for  Blanchard  grinder, 

211. 

Wheel  speed  for  cylindrical  grinding, 

223. 
Wheel  speed  for  roll  grinding,  269, 

273- 

Wheel  speed,  rule  for  finding,  224. 
Wheel  speeds  for  internal  grinding, 

254-  . 

Wheel  test  data,  101. 
Wheel  truing  diamond,  setting  of,  134. 
Wheel  truing  diamonds,  kinds  of,  133. 
Wheel  wear,  effect  of,  in  cam  grinding, 

285. 

Wheel  wear,  rapid,  104. 
Wheels,  elastic,  purposes  used  for,  80. 
Wheels  for  Blanchard  grinder,  212. 
Wheels  for  cam  grinding,  283. 
Wheels  for  crankshaft  grinding,  278. 
Wheels  for  cutter  grinding,  305. 
Wheels  for  cylinder  grinding,  259. 
Wheels  for  cylindrical  grinding,  235. 
Wheels  for  die  grinding,  188,  192,  199. 
Wheels  for  flour  mill  roll  grinding, 274. 
Wheels  for  link  grinding,  289. 


Wheels  for  roll  grinding,  268. 

Wheels,  pressed,  characteristics  of,  68. 

Wheels,  selection  of,  for  surfacing, 
187. 

Wheels,  silicate,  purposes  used  for, 
79- 

Wheels,  soft,  limits  in  using,  104. 

Wheels,  unguarded,  157. 

Wheels  used  for  rough  operations,  ma- 
chine for  testing,  116. 

Wheels  used  for  saw  grinding,  313. 

Wheels,  wide  faced  for  cutter  grind- 
ing, 294. 

Why  Carborundum  is  not  found  in 
nature,  41. 

Why  corundum  is  not  used  more  ex- 
tensively, 26. 

Williams,  Richard  G.,  57. 

Wire  web  grinding  wheels,  80,  124. 

Wood  working  saws,  types  of,  308. 

Work  carrying  fixtures  for  crankshaft 
grinding,  275. 

Work  rest,  154. 

Work  rests  as  cause  of  accidents,  155. 

Work  speed,  223. 

Work  speed  for  roll  grinding,  269,  273. 


THE    END 


1919 

CATALOGUE 

of  the  Latest  and  Best 

Practical  and  Mechanical  Books 

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PRACTICAL  BOOKS  FOR  PRACTICAL  MEN 

Each  Book  in  this  Catalogue  is  written  by  an 
Expert  and  is  written  so  you  can  understand  it 


PUBLISHED  BY 

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2  West  45th  Street,  New  York,  U.  S.  A. 

Established  1890 
Any  Book  in  this  Catalogue  sent  prepaid  on  receipt  of  price 


INDEX 


PAGE 

Air  Brakes  .......................  23,  26 

Arithmetic  ...................  14,  27,  35 

Automobile  Books  ................  3,  4,  5 

Automobile  Carburetors  ...........          5 

Automobile  Charts  ...............          6 

Automobile  Ignition  Systems  .......          4 

Automobile  Lighting  ..............          4 

Automobile  Questions  and  Answers  .          4 
Automobile  Repairing  .............          3 

Automobile  Starting  Systems  ......          4 

Automobile  Trouble  Chart  ........          6 

Automobile  Welding  ..............          5 

Aviation  .........................          7 

Aviation  Chart  ...................          6 

Bevel  Gear  ......................        21 

Boiler  Room  Chart  ...............          9 

Brazing  .........................          8 

Cams  ...........................        21 

Carburetion  Trouble  Chart  ........          6 

Carburetors  ......................          5 

Change  Gear  ......................  21 

Charts  ..........................     6,  7 

Coal  ............................  24,  30 

Coke  ............................        10 

Combustion  ..........  ............        24 

Compressed  Air  ..................        10 

Concrete  ...............  ......  10,  11,  12 

Concrete  for  Farm  Use  ............        12 

Concrete  for  Shop  Use  ............        12 

Cosmetics  .......................        31 

Cyclecars  ....................  ____          5 

Dictionary  .......................  12,  13 


Dies 

Drawing 

Drawing  for  Plumbers 

DropFo    ' 

Dynamo 

Electric  Bells 

Electric  Switchboards  .............  15,  17 

Electric  Toy  Making  ..............        15 

Electric  Wiring  ...............  15,  16,  17 

Electricity  .................  15,  16,  17,18 

26 


E-T  Air  Brake 

"  Everyday  Engineering  " 

Factory  Management 

Ford  Automobile 

Ford  Trouble  Chart 

Formulas  and  Recipes 

Fuel 

8 as  Engine  Construction 
as  Engines 19,  20,  21 

Gas  Tractor 37 

Gearing  and  Cams 


Heating 

High  Frequency  Apparatus 

Horse  Power  Chart 

Hot  Water  Heating 

House  Wiring 

Hydraulics 

Ice 

Ignition  Systems , 

Ignition  Trouble  Chart 

India  Rubber 

Interchangeable  Manufacturing ... 

Inventions , 

Knots 

Lathe  Work 

Link  Motions 


•21 


PAGE 

Liquid  Air. .  , 23 

Locomotive  Boilers 24 

Locomotive  Breakdowns 24 

Locomotive  Engineering.  .  .  .23,  24,  25,  26 

Machinist  Books 26,  27,  28,  29 

Manual  Training 

Marine  Engineering 

Marine  Gasoline  Engines 

Mechanical  Drawing 

Mechanical  Movements 

Metal  Work .  . 


Mining 
odel 


29 
20 
14 
28 
13 
30 
29 
5 

22 
31 
31 
14 

32,  33 
21 
13 


Model  Making 

Motorcycles 

Patents 

Pattern  Making 

Perfumery 

Perspective 

Plumbing 

Producer  Gas 

Punches 

Questions    and    Answers    on    Auto- 
mobile    4 

Questions  on  Heating 36 

Radio 17 

Railroad  Accidents 25 

Railroad  Charts 9 

Recipe  Book 33 

Refrigeration 22 

Repairing  Automobiles 3 

Rope  Work 22 

Rubber 34 

Rubber  Stamps 34 

Saw  Filing 34 

Saws,  Management  of 34 

Sheet  Metal  Works 13 

Shop  Construction 19 

Shop  Management 19 

Shop  Practice 19 

Shop  Tools 28 

Sketching  Paper 14 

Soldering 8 

Splices  and  Rope  Work 22 

Steam  Engineering 34,  35,  36 

Steam  Heating 36 

Steel 37 

Storage  Batteries 18 

Submarine  Chart 30 

Switch  Boards 15,  17  , 


Tapers 

Telegraphy,  Wireless 

Telephone 

Thread  Cutting ' 

Tool  Making 

Toy  Making 

Tractive  Power  Chart 

Tractor,  Gas 

Tram  Rules 

Turbines 

Vacuum  Heating 

Valve  Setting 

Ventilation 

Walschaert  Valve  Gear 

Waterproofing 

Welding .-. 

Wireless  Telegraphy K 


Wiring 

Wiring  Diagrams 


25 

:<7 
M 
_>4 
:<i> 
_'G 
l_' 
0 

,  18 

.  .15,  16,  17 
15 


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handled,  both  in  the  text  and  in  the  matter  of  illustrations." — The  Motorist. 
"The  book  is  very  thorough,  a  careful  examination  failing  to  disclose  any  point  in 
connection  with  the  automobile,  its  care  and  repair,  to  have  been  overlooked."— 
Iron  Age. 

"Mr.  Page  has  done  a  great  work,  and  benefit  to  the  Automobile  Field."— W.  O. 
Hasford,  Mgr.  Y.  M.  C.  A.  Automobile  School,  Boston,  Mass. 

"It  is  just  the  kind  of  a  book  a  motorist  needs  if  he  wants  to  understand  his  car." — • 
American  Thresherman. 

THE  MODEL  T  FORD  CAR,  ITS  CONSTRUCTION,  OPERATION  AND 
REPAIR,  INCLUDING  THE  FORD  FARM  TRACTOR.  By  VICTOR  W. 
PAGE,  M.E. 

This  is  a  complete  instruction  book.  All  parts  of  the  Ford  Model  T  Car  are  described 
and  illustrated;  the  construction  is  fully  described  and  operating » principles  made 
clear  to  everyone.  Every  Ford  owner  needs  this  practical  book.  You  don't  have  to 
guess  about  the  construction  or  where  the  trouble  is,  as  it  shows  how  to  take  all  parts 
apart  and  how  to  locate  and  fix  all  faults.  The  writer,  Mr.  Page',  has  operated  a  Ford 
car  for  four  years  and  writes  from  actual  knowledge.  Among  the  contents  are: 
1.  The  Ford  Car.  Its  Parts  and  Their  Functions.  2.  The  Engine  and  Auxiliary 
Groups.  How  the  Engine  Works — The  Fuel  Supply  System — The  Carburetor — • 
Making  the  Ignition  Spark — Cooling  and  Lubrication.  3.  Details  of  Chassis. 
Change  Speed  Gear — Power  Transmission— Differential  Gear  Action— Steering  Gear 
— Front  Axle — Frame  and  Springs — Brakes.  4.  How  to  Drive  and  Care  for  the  Ford. 
The  Control  System  Explained— Starting  the  Motor— Driving  the  Car— Locating 
Roadside  Troubles— Tire  Repairs — Oiling  the  Chassis — Winter  Care  of  Car.  5.  Sys- 
tematic Location  of  Troubles  and  Remedies.  Faults  in  Engine — Faults  in  Carburetor 
—Ignition  Troubles— Cooling  and  Lubrication  System  Defects — Adjustment  of 
Transmission  Gear — General  Chassis  Repairs.  The  Ford  Tractor  and  Tractor  con- 
version sets  and  Genuine  Ford  Tractor.  106  illustrations.  310  pages.  Two  large 
folding  plates.  Price  .  .  $1.00 

AUTOMOBILE  REPAIRING  MADE  EASY.    By  VICTOR  W.  PAG£,  M.E. 
A  comprehensive,  practical  exposition  of  every  phase  of  modern  automobile  repairing 
practice.     Outlines  every  process  incidental  to  motor  car  restoration.     Gives  plans  for 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

workshop  construction,  suggestions  for  equipment,  power  needed,  machinery  and  tools 
necessary  to  carry  on  the  business  successfully.  Tells  how  to  overhaul  and  repair  all 
parts  of  all  automobiles.  Everything  is  explained  so  simply  that  motorists  and  students 
can  acquire  a  full  working  knowledge  of  automobile  repairing.  This  work  starts  with 
the  engine,  then  considers  carburetion,  ignition,  cooling  and  lubrication  systems.  The 
clutch,  change  speed  gearing  and  transmission  system  are  considered  in  detail.  Contains 
instructions  for  repairing  all  types  of  axles,  steering  gears  and  other  chassis  parts. 
Many  tables,  short  cuts  in  figuring  and  rules  of  practice  are  given  for  the  mechanic. 
Explains  fully  valve  and  magneto  timing,  "tuning"  engines,  systematic  location  of 
trouble,  repair  of  ball  and  roller  bearings,  shop  kinks,  first  aid  to  injured  and  a  multi- 
tude of  subjects  of  interest  to  all  in  the  garage  and  repair  business. 
This  book  contains  special  instructions  on  electric  starling,  lighting  and  ignition  systems, 
tire  repairing  and  rebuilding,  autogenous  welding,  brazing  and  soldering,  heat  treatment  of 
steel,  latest  timing  practice,  eight  and  twelve-cylinder  motors,  etc.  5^x8.  Cloth.  1056 
pages,  1,000  illustrations,  11  folding  plates.  Price $3.50 

WHAT  IS  SAID  OF  THIS  BOOK: 

"  'Automobile  Repairing  Made  Easy '  is  the  best  book  on  the  subject  I  have  ever  seen 
and  the  only  book  I  ever  saw  that  is  of  any  value  in  a  garage." — Fred  Jeffrey,  Martins- 
burg,  Neb. 

"I  wish  to  thank  you  for  sending  me  a  copy  of  'Automobile  Repairing  Made  Easy.*  I 
do  not  think  it  could  be  excelled."— S.  W.  Gisriel,  Director  of  Instruction,  Y.  M.  C.  A.. 
Philadelphia,  Pa. 

QUESTIONS  AND  ANSWERS   RELATING  TO   MODERN  AUTOMOBILE 
CONSTRUCTION,  DRIVING  AND  REPAIR.     By  VICTOR  W.  PAGE,  M.E. 

A  practical  self-instructor  for  students,  mechanics  and  motorists,  consisting  of  thirty- 
seven  lessons  in  the  form  of  questions  and  answers,  written  with  special  reference  to  the 
requirements  of  the  non-technical  reader  desiring  easily  understood,  explanatory 
matter  relating  to  all  branches  of  automobiling.  The  subject-matter  is  absolutely 
correct  and  explained  in  simple  language.  If  you  can't  answer  all  of  the  following 
questions,  you  need  this  work.  The  answers  to  these  and  nearly  2000  more  are  to 
be  found  in  its  pages.  Give  the  name  of  all  important  parts  of  an  automobile  and 
describe  their  functions?  Describe  action  of  latest  types  of  kerosene  carburetors? 
What  is  the  difference  between  a  "double"  ignition  system  and  a  "dual"  ignition 
system?  Name  parts  of  an  induction  coil?  How  are  valves  timed?  What  is  an 
electric  motor  starter  and  how  does  it  work?  What  are  advantages  of  worm  drive 
gearing?  Name  all  important  types  of  ball  and  roller  bearings?  What  is  a  "three- 
quarter"  floating  axle?  What  is  a  two-speed  axle?  What  is  the  Vulcan  electric  gear 
shift?  Name  the  causes  of  lost  power  hi  automobiles?  Describe  all  noises  due  to 
deranged  mechanism  and  give  causes?  How  can  you  adjust  a  carburetor  by  the 
color  of  the  exhaust  gases?  What  causes  "popping"  in  the  carburetor?  What  tools 
and  supplies  are  needed  to  equip  a  car?  How  do  you  drive  various  makes  of  cars? 
What  is  a  differential  lock  and  where  is  it  used?  Name  different  systems  of  wire 
wheel  construction,  etc.,  etc.  A  popular  work  at  a  popular  price.  5M  x7  Y2.  Cloth. 
650  pages,  350  illustrations,  3  folding  plates.  Price $2.00 

WHAT  IS  SAID  OF  THIS  BOOK: 
"If  you  own  a  car — get  this  book." — The  Glassworker. 

"Mr.  Page  has  the  faculty  of  making  difficult  subjects  plain  and  understandable." — 
Bristol  Press. 

"We  can  name  no  writer  better  qualified  to  prepare  a  book  of  instruction  on  auto- 
mobiles than  Mr.  Victor  W.  Page." — Scientific  American. 
"The  best  automobile  catechism  that  has  appeared." — Automobile  Topics. 
"  There  are  few  men,  even  with  long  experience,  who  will  not  find  this  book  useful. 
Great  pains  have  been  taken  to  make  it  accurate.     Special  recommendation  must  be 
given  to  the  illustrations,  which  have  been  made  specially  for  the  work.     Such  ex- 
cellent books  as  this  greatly  assist  in  fully  understanding  your  automobile." — En- 
gineering News. 

MODERN  STARTING,  LIGHTING  AND  IGNITION  SYSTEMS.    By  VICTOR 
W.  PAGE,  M.E. 

This  practical  volume  has  been  written  with  special  reference  to  the  requirements  of  the 
non-technical  reader  desiring  easily  understood,  explanatory  matter,  relating  to  all 
types  of  automobile  ignition,  starting  and  lighting  systems.  It  can  be  understood  by 
anyone,  even  without  electrical  knowledge,  because  elementary  electrical  principles  are 
considered  before  any  attempt  is  made  to  discuss  features  of  the  various  systems. 
These  basic  principles  are  clearly  stated  and  illustrated  with  simple  diagrams.  All  the 
leading  systems  of  starling,  lighting  and  ignition  have  been  described  and  illustrated  with 
the  co-operation  of  the  experts  employed  by  the  manufacturers.  Wiring  diagrams  ar« 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


shown  in  both  technical  and  non-  technical  forms.  All  symbols  are  fully  explained.  It 
is  a  comprehensive  review  of  modern  starting  and  ignition  system  practice,  and  includes 
a  complete  exposition  of  storage  battery  construction,  care  and  repair.  All  types  of 
starting  motors,  generators,  magnetos,  and  all  ignition  or  lighting  system  units  are 
fully  explained.  The  systems  of  cars  already  in  use  as  well  as  those  that  are  to  come 
in  1919  are  considered.  Every  person  in  the  automobile  business  needs  this  volume. 
.  Cloth.  530  pages,  297  illustrations,  3  folding  plates.  Price  .  .  $2.0O 


GASOLINE  AND  KEROSENE  CARBURETORS,  CONSTRUCTION,  IN- 
STALLATION AND  ADJUSTMENT.  By  MAJOR  VICTOR  W.  PAGE.  A 
New  Up-to-date  Book  on  Modern  Carburetion  Practice. 

This  is  a  simple,  comprehensive,  and  authoritative  treatise  for  practical  men  ex- 
plaining all  basic  principles  pertaining  to  carburetion,  showing  how  liquid  fuels  are 
vaporized  and  turned  into  gas  for  operating  all  types  of  internal  combustion  engines  in- 
tended to  operate  on  vapors  of  gasoline,  kerosene,  benzol,  and  alcohol.  All  leading  types 
of  carburetors  are  described  in  detail,  special  attention  being  given  to  the  forms  devised 
to  use  the  cheaper  fuels  such  as  kerosene.  Carburetion  troubles,  fuel  system  troubles, 
carburetor  repairs  and  installation,  electric  primers  and  economizers,  hot  spot  mani- 
folds and  all  modern  carburetor  developments  are  considered  in  a  thorough  manner. 
Methods  of  adjusting  all  types  of  carburetors  are  fully  discussed  as  well  as  sugges- 
tions for  securing  maximum  fuel  economy  and  obtaining  highest  engine  power. 
This  book  is  invaluable  to  repairmen,  students,  and  motorists,  as  it  includes  the 
most  complete  exposition  on  kerosene  carburetors  ever  published.  The  drawings 
showing  carburetor  construction  are  made  from  accurate  engineering  designs  and 
show  all  parts  of  late  types  of  carburetors.  250  pages.  89  illustrations.  .  $1.50 

HOW  TO  RUN  AN  AUTOMOBILE.    By  VICTOR  W.  PAGE. 

This  treatise  gives  concise  instructions  for  starting  and  running  all  makes  of  gasoline 
automobiles,  how  to  care  for  them,  and  gives  distinctive  features  of  control.  De- 
scribes every  step  for  shifting  gears,  controlling  engine,  etc.  Among  the  chapters 
contained  are:  I.  Automobile  Parts  and  Their  Functions.  II.  General  Starting 
and  Driving  Instructions.  III.  Typical  1919  Control  Systems  —  Care  of  Auto- 
mobiles. Thoroughly  illustrated.  178  pages.  72  illustrations.  Price  .  .  $1.00 

THE  AUTOMOBILIST'S  POCKET  COMPANION  AND  EXPENSE  RECORD. 
By  VICTOR  W.  PAGE. 

This  book  is  not  only  valuable  as  a  convenient  cost  record,  but  contains  much  in- 
formation of  value  to  motorists.  Includes  a  condensed  digest  of  auto  laws  of  all 
States,  a  lubrication  schedule,  hints  for  care  of  storage  battery,  and  care  of  tires, 
location  of  road  troubles,  anti-freezing  solutions,  horse-power  table,  driving  hints 
and  many  useful  tables  and  recipes  of  interest  to  ah1  motorists.  Not  a  technical 
book  in  any  sense  of  the  word,  just  a  collection  of  practical  facts  in  simple  language 
for  the  every-day  motorist.  Convenient  pocket  size.  Price  .'....  $1.00 

AUTOMOBILE    WELDING    WITH  THE  OXY-ACETYLENE  FLAME.J    By 
M.  KEITH  DUNHAM. 

Explains  in  a  simple  manner  apparatus  to  be  used,  its  care,  and  how  to  construct 
necessary  shop  equipment.  Proceeds  then  to  the  actual  welding  of  .all  automobile 
parts,  in  a  manner  understandable  by  every  one.  Gives  principles  never  to  be  for- 
gotten. This  book  is  of  utmost  value,  since  the  perplexing  problems  arising  when 
metal  is  heated  to  a  melting  point  are  fully  explained  and  the  proper  methods  to 
overcome  them  shown.  167  pages.  Fully  illustrated.  Price  .....  $1.25 

MOTORCYCLES,  SIDE  CARS  AND  CYCLECARS,  THEIR  CONSTRUCTION, 
MANAGEMENT  AND  REPAIR.  By  VICTOR  W.  PAGE,  M.E. 

The  only  complete  work  published  for  the  motorcyclist  and  cyclecarist.  Describes 
fully  all  leading  types  of  machines,  their  design,  construction,  maintenance,  operation 
and  repair.  This  treatise  outlines  fully  the  operation  of  two-  and  four-cycle  power 
plants  and  all  ignition,  carburetion  and  lubrication  systems  in  detail.  Describes  all 
representative  types  of  free  engine  clutches,  variable  speed  gears  and  power  trans- 
mission systems.  Gives  complete  instructions  for  operating  and  repairing  all  types. 
Considers  fully  electric  self-starting  and  lighting  systems,  all  types  of  spring  frames 
and  springs  forks  and  shows  leading  control  methods.  For  those  desiring  technical 
information  a  complete  series  of  tables  and  many  formulae  to  assist  in  designing  are 
included.  The  work  tells  how  to  figure  power  needed  to  climb  grades,  overcome  air 
resistance  and  attain  high  speeds.  It  shows  how  to  select  gear  ratios  for  various 
weights  and  powers,  how  to  figure  braking  efficiency  required,  gives  sizes  of  belts  and 
chains  to  transmit  power  safely,  and  shows  how  to  design  sprockets,  belt  pulleys,  etc. 
This  work  also  includes  complete  formulae  for  figuring  horse-power,  shows  how  dyna- 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 

mometer  tests  are  made,  defines  relative  efficiency  of  air-  and  water-cooled  engines,  plain 
and  anti-friction  bearings  and  many  other  data  of  a  practical,  helpful,  engineering 
nature.  Remember  that  you  get  this  information  in  addition  to  the  practical  de- 
scription and  instructions  which  alone  arc  worth  several  times  the  price  of  the  book. 
550  pages.  350  specially  made  illustrations,  5  folding  plates.  Cloth.  Price  .  $2.00 

WHAT  IS  SAID  OP  THIS  BOOK: 

"  Here  Is  a  book  that  should  be  in  the  cycle  repairer's  kit." — American  Blacksmith. 
"  The  best  way  for  any  rider  to  thoroughly  understand  his  machine,  is  to  get  a  copy 
of  this  book;  it  is  worth  many  times  its  price." — Pacific  Motorcyclist. 

AUTOMOBILE,  AVIATION  AND  MOTORCYCLE  CHARTS 

AVIATION  CHART— LOCATION  OF  AIRPLANE  POWER  PLANT  TROUBLES 
MADE  EASY.  By  MAJOR  VICTOR  W.  PAGE,  A.S.,  S.C.U.S.R. 
A  large  chart  outlining  all  parts  of  a  typical  airplane  power  plant, .showing  the  points 
where  trouble  is  apt  to  occur  and  suggesting  remedies  for  the  common  defects.  In- 
tended especially  for  aviators  and  aviation  mechanics  on  school  and  field  duty. 
Price 50  cents 

CHART.  GASOLINE  ENGINE  TROUBLES  MADE  EASY— A  CHART  SHOW- 
ING SECTIONAL  VIEW  OF  GASOLINE  ENGINE.  Compiled  by  VICTOR 
W.  PAGE,  M.E.  ^ 

It  shows  clearly  all  parts  of  a  typical  four-cylinder  gasoline  engine  of  the  four-cycle 
type.  It  outlines  distinctly  all  parts  liable  to  give  trouble  and  also  details  the  de- 
rangements apt  to  interfere  with  smooth  engine  operation. 

Valuable  to  students,  motorists,  mechanics,  repairmen,  garagemen,  automobile  sales- 
men, chauffeurs,  motorboat  owners,  motor-truck  and  tractor  drivers,  aviators,  motor- 
cyclists, and  all  others  who  have  to  do  with  gasoline  power  plants. 
It  simplifies  location  of  all  engine  troubles,  and  while  it  will  prove  invaluable  to  the 
novice,  it  can  be  used  to  advantage  by.  the  more  expert.  It  should  be  on  the  walls  of 
every  public  and  private  garage,  automobile  repair  shop,  clubhouse  or  school.  It  can 
be  carried  in  the  automobile  or  pocket  with  ease,  and  will  insure  against  loss  of  time 
when  engine  trouble  manifests  itself. 

This  sectional  view  of  engine  is  a  complete  review  of  all  motor  troubles.  It  is  prepared 
by  a  practical  motorist  for  all  who  motor.  More  information  for  the  money  than  ever 
before  offered.  No  details  omitted.  Size  25x38  inches.  Securely  mailed  on  receipt 
of 25  cents 

CHART.  LOCATION  OF  FORD  ENGINE  TROUBLES  MADE  EASY.  Com- 
piled by  VICTOR  W.  PAGE,  M.E. 

This  shows  clear  sectional  views  depicting  all  portions  of  the  Ford  power  plant  and 
auxiliary  groups.  It  outlines  clearly  all  parts  of  the  engine,  fuel  supply  system,  igni- 
tion group  and  cooling  system,  that  are  apt  to  give  trouble,  detailing  all  derangements 
that  are  liable  to  make  an  engine  lose  power,  start  hard  or  work  irregularly.  This 
chart  is  valuable  to  students,  owners,  and  drivers,  as  it  simplifies  location  of  all  engine 
faults.  Of  great  advantage  as  an  instructor  for  the  novice,  it  can  be  used  equally  well 
by  the  more  expert  as  a  work  of  reference  and  review.  It  can  be  carried  in  the  tool- 
box or  pocket  with  ease  and  will  save  its  cost  in  labor  eliminated  the  first  time  engine 
trouble  manifests  itself.  Prepared  with  special  reference  to  the  average  man's  needs 
and  is  a  practical  review  of  all  motor  troubles  because  it  is  based  on  the  actuaj  ex- 
perience of  an  automobile  engineer-mechanic  with  the  mechanism  the  chart  describes. 
It  enables  the  non-technical  owner  or  operator  of  a  Ford  car  to  locate  engine  de- 
rangements by  systematic  search,  guided  by  easily  recognized  symptoms  instead  of  by 
guesswork.  It  makes  the  average  owner  independent  of  the  roadside  repair  shop 
when  touring.  Must  be  seen  to  be  appreciated.  Size  25x38  inches.,  Printed  on 
heavy  bond  paper.  Price 25  cents 

CHART.  LUBRICATION  OF  THE  MOTOR  CAR  CHASSIS.  Compiled  by 
VICTOR  W.  PAGE,  M.E. 

This  chart  presents  the  plan  view  of  a  typical  six-cylinder  chassis  of  standard  design 
and  all  parts  are  clearly  indicated  that  demand  oil,  also  the  frequency  with  which  they 
must  be  lubricated  and  the  kind  of  oil  to  use.  A  practical  chart  for  all  interested  in 
motor-car  maintenance.  Size  24x38  inches.  Price 25  cents 

CHART.  LOCATION  OF  CARBURETION  TROUBLES  MADE  EASY.  Com- 
piled by  VICTOR  W.  PAGE,  M.E. 

This  chart  shows  all  parts  of  a  typical  pressure  feed  fuel  supply  system  and  gives 
causes  of  trouble,  how  to  locate  defects  and  means  of  remedying  them.  Size  24x38 
inches.  Price 25  cents 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

CHART.     LOCATION  OF  IGNITION  SYSTEM  TROUBLES  MADE  EASY. 
Compiled  by  VICTOR  W.  PAGE,  M.E. 

In  this  diagram  all  parts  of  a  typical  double  ignition  system  using  battery  and  magneto 
current  are  shown,  and  suggestions  are  given  for  readily  finding  ignition  troubles  and 
eliminating  them  when  found.  Size  24x38  inches.  Price 25  cents 

CHART.    LOCATION  OF  COOLING  AND  LUBRICATION  SYSTEM  FAULTS. 
Compiled  by  VICTOR  W.  PAGE,  M.E. 

This  composite  diagram  shows  a  typical  automobile  power  plant  using  pump  circulated 
water-cooling  system  and  the  most  popular  lubrication  method.  Gives  suggestions 
for  curing  all  overheating  and  loss  of  power  faults  due  to  faulty  action  of  the  oiling 
or  cooling  group.  Size  24x38  inches.  Price 25  cents 

CHART.     MOTORCYCLE  TROUBLES  MADE  EASY.    Compiled  by  VICTOR 
W.  PAGE,  M.E. 


A  chart  showing  sectional  view  of  a  single-cylinder  gasoline  engine.  This  chart 
simplifies  location  of  all  power-plant  troubles.  A  single-cylinder  motor  is  shown  for 
simplicity.  It  outlines  distinctly  all  parts  liable  to  give  trouble  and  also  details  the 


derangements  apt  to  interfere  with  smooth  engine  operation.  This  chart  will  prove 
of  value  to  all  who  have  to  do  with  the  operation,  repair  or  sale  of  motorcycles.  No 
details  omitted.  Size  30x20  inches.  Price  25  cents 

AVIATION 


A  B  C  OF  AVIATION    By  MAJOR  VICTOR  W.  PAGE. 

This  book  describes  the  basic  principles  of  aviation,  tells  how  a  balloon  or  dirigible 
is  made  and  why  it  floats  in  the  air.  Describes  how  an  airplane  flies.  It  shows  in 
detail  the  different  parts  of  an  airplane,  what  they  are  and  what  they  do.  Describes 
all  types  of  airplanes  and  how  they  differ  in  construction;  as  well  as  detailing  the 
advantages  and  disadvantages  of  different  types  of  aircraft.  It  includes  a  complete 
dictionary  of  aviation  terms  and  clear  drawings  of  leading  airplanes.  The  reader 
will  find  simple  instructions  for  unpacking,  setting  up,  and  rigging  airplanes.  A 
full  description  of  airplane  control  principles  is  given  and  methods  of  flying  are  dis- 
cussed at  length. 

This  book  answers  every  question  one  can  ask  about  modern  aircraft,  their  con- 
struction and  operation.  A  self-educator  on  aviation  without  an  equal.  275  pages. 
130  specially  made  illustrations  with  7  plates.  Price $2.50 

AVIATION  ENGINES— DESIGN;  CONSTRUCTION;  REPAIR.  By  MAJOR 
VICTOR  W.  PAGE,  A.S.,  S.C.U.S.R. 

This  treatise,  written  by  a  recognized  authority  on  all  of  the  practical  aspects  of 
internal  combustion  engine  construction,  maintenance,  and  repair,  fills  the  need  as 
no  other  book  does.  The  matter  is  logically  arranged;  all  descriptive  matter  is 
simply  expressed  and  copiously  illustrated,  so  that  anyone  can  understand  airplane 
engine  operation  and  repair  even  if  without  previous  mechanical  training.  This 
work  is  invaluable  for  anyone  desiring  to  become  an  aviator  or  aviation  mechanic. 
The  latest  rotary  types,  such  as  the  Gnome  Monosoupape,  and  LeRhone,  are  fully 
explained,  as  well  as  the  recently  developed  Vee  and  radial  types.  The  subjects 
of  carburetion,  ignition,  cooling,  and  lubrication  also  are  covered  in  a  thorough  manner. 
The  chapters  on  repair  and  maintenance  are  distinctive  and  found  in  no  other  book 
on  this  subject.  Not  a  technical  book,  but  a  practical,  easily  understood  work  of 
reference  for  all  interested  in  aeronautical  science.  576  pages.  253  illustrations. 
Price,  net $3.00 

GLOSSARY  OF  AVIATION  TERMS  — ENGLISH-FRENCH;  FRENCH- 
ENGLISH.  By  MAJOR  VICTOR  W.  PAGE,  A.S.,  S.C.U.S.R.,  and  LIEUT. 
PAUL  MONTARIOL,  of  the  French  Flying  Corps. 

A  complete  glossary  of  practically  all  terms  used  in  aviation,  having  lists  in  both 
French  and  English  with  equivalents  in  either  language.  Price,  net  .  .  $1.00 

AVIATION  CHART— LOCATION  OF  AIRPLANE  POWER  PLANT  TROUBLES 
MADE  EASY.  By  MAJOR  VICTOR  W.  PAGE,  A.S.,  S.C.U.S.R. 

A  large  chart  outlining  all  parts  of  a  typical  airplane  power  plant,  showing  the  points 
where  trouble  is  apt  to  occur  and  suggesting  remedies  for  the  common  defects.  In- 
tended especially  for  aviators  and  aviation  mechanics  on  school  and  field  duty. 
Price 50  cents 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


BRAZING  AND  SOLDERING 

BRAZING  AND  SOLDERING.    By  JAMES  F.  HOBART. 

The  only  book  that  shows  you  just  how  to  handle  any  job  of  brazing  or  soldering  that 
comes  along:  it  tells  you  what  mixture  to  use,  how  to  make  a  furnace  if  you  need  one. 
Full  of  valuable  kinks.  The  fifth  edition  of  this  book  has  just  been  published,  and  to 
it  much  new  matter  and  a  large  number  of  tested  formulae  for  all  kinds  of  solders  and 
fluxes  have  been  added.  Illustrated 35  cents 

CHARTS 

AVIATION  CHART— LOCATION  OF  AIRPLANE  POWER  PLANT  TROUBLES 
MADE  EASY.     By  MAJOR  VICTOR  W.  PAGE,  A.S.,  S.C.U.S.R. 

A  large  chart  outlining  all  parts  of  a  typical  airplane  power  plant,  showing  the  points 
where  trouble  is  apt  to  occur  and  suggesting  remedies  for  the  common  defects. 
Intended  especially  for  aviators  and  aviation  mechanics  on  school  and  field  duty. 
Price 50  cents 


GASOLINE  ENGINE  TROUBLES  MADE  EASY— A  CHART  SHOWING  SEC- 
TIONAL VIEW  OF  GASOLINE  ENGINE.  Compiled  by  VICTOR  W.  PAGE. 
It  shows  clearly  all  parts  of  a  typical  four-cylinder  gasoline  engine  of  the  four-cycle 
type.  It  outlines  distinctly  all  parts  liable  to  give  trouble  and  also  details  the  de- 
rangements apt  to  interfere  with  smooth  engine  operation. 

Valuable  to  students,  motorists,  mechanics,  repairmen,  garagemen,  automobile  sales- 
men, chauffeurs,  motor-boat  owners,  motor-truck  and  tractor  drivers,  aviators,  motor- 
cyclists, and  all  others  who  have  to  do  with  gasoline  power  plants. 
It  simplifies  location  of  all  engine  troubles,  and  while  it  will  prove  invaluable  to  the 
novice,  it  can  be  used  to  advantage  by  the  more  expert.  It  should  be  on  the  walls  of 
every  public  and  private  garage,  automobile  repair  shop,  club  house  or  school.  It  can 
be  carried  in  the  automobile  or  pocket  with  ease  and  will  insure  against  loss  of  time 
when  engine  trouble  manifests  itself. 

This  sectional  view  of  engine  is  a  complete  review  of  all  motor  troubles.  It  is  pre- 
pared by  a  practical  motorist  for  all  who  motor.  No  details  omitted.  Size  25x38 
inches 25  cents 

LUBRICATION  OF  THE  MOTOR  CAR  CHASSIS. 

This  chart  presents  the  plan  view  of  a  typical  six-cylinder  chassis  of  standard  design 
and  all  parts  are  clearly  indicated  that  demand  oil,  also  the  frequency  with  which  they 
must  be  lubricated  and  the  kind  of  oil  to  use.  A  practical  chart  for  all  interested  in 
motor-car  maintenance.  Size  24x38  inches.  Price 25  cents 

LOCATION  OF  CARBURETION  TROUBLES  MADE  EASY. 

This  chart  shows  all  parts  of  a  typical  pressure  feed  fuel  supply  system  and  gives 
causes  of  trouble,  how  to  locate  defects  and  means  of  remedying  them.  Size  24x38 
inches.  Price 25  cents 

LOCATION  OF  IGNITION  SYSTEM  TROUBLES  MADE  EASY. 

In  this  chart  all  parts  of  a  typical  double  ignition  system  using  battery  and  magneto 
current  are  shown  and  suggestions  are  given  for  readily  finding  ignition  troubles  and 
eliminating  them  when  found.  Size  24x38  inches.  Price 25  cents 

LOCATION  OF  COOLING  AND  LUBRICATION  SYSTEM  FAULTS. 

This  composite  chart  shows  a  typical  automobile  power  plant  using  pump  circulated 
water-cooling  system  and  the  most  popular  lubrication  method.  Gives  suggestions 
for  curing  all  overheating  and  loss  of  bower  faults  due  to  faulty  action  of  the  oiling  or 
cooling  group.  Size  24x38  inches.  Price 25  cents 

MOTORCYCLE  TROUBLES  MADE  EASY— A  CHART  SHOWING  SEC- 
TIONAL VIEW  OF  SINGLE-CYLINDER  GASOLINE  ENGINE.  Compiled 
by  VICTOR  W.  PAGE. 

This  chart  simplifies  location  of  all  power-plant  troubles,  and  will  prove  invaluable  to 
all  who  have  to  do  with  the  operation,  repair  or  sale  of  motorcycles.     No  details 
Size  25x38  inches.     Price 25  cents 

8 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

LOCATION  OF  FORD  ENGINE  TROUBLES  MADE  EASY.    Compiled   by 
VICTOR  W.  PAGE,  M.E. 

This  shows  clear  sectional  views  depicting  all  portions  of  the  Ford  power  plant  and 
auxiliary  groups.  It  outlines  clearly  all  parts  of  the  engine,  fuel  supply  system, 
ignition  group  and  cooling  system,  that  are  apt  to  give  trouble,  detailing  all  derange- 
ments that  are  liable  to  make  an  engine  lose  power,  start  hard  or  work  irregularly.  This 
chart  is  valuable  to  students,  owners,  and  drivers,  as  it  simplifies  location  of  all  engine 
faults.  Of  great  advantage  as  an  instructor  for  the  novice,  it  can  be  used  equally  well 
by  the  more  expert  as  a  work  of  reference  and  review.  It  can  be  carried  in  the  tool- 
box or  pocket  with  ease  and  will  save  its  cost  in  labor  eliminated  the  first  time  engine 
trouble  manifests  itself.  Prepared  with  special  reference  to  the  average  man's  needs 
and  is  a  practical  review  of  all  motor  troubles  because  it  is  based  on  the  actual  ex- 
perience of  an  automobile  engineer-mechanic  with  the  mechanism  the  chart  describes. 
It  enables  the  non-technical  owner  or  operator  of  a  Ford  car  to  locate  engine  de- 
rangements by  systematic  search,  guided  by  easily  recognized  symptoms  instead  of  by 
guesswork.  It  makes  the  average  owner  independent  of  the  roadside  repair  shop 
when  touring.  Must  be  seen  to  be  appreciated.  Size  25x38  inches.  Printed  on  heavy 
bond  paper.  Price 25  cents 

MODERN  SUBMARINE  CHART  — WITH  200  PARTS  NUMBERED  AND 
NAMED. 

A  cross-section  view,  showing  clearly  and  distinctly  all  the  interior  of  a  Submarine  of 
the  latest  type.  You  get  more  information  from  this  chart,  about  the  construction  and 
operation  of  a  Submarine,  than  in  any  other  way.  No  details  omitted — everything 
is  accurate  and  to  scale.  It  is  absolutely  correct  in  every  detail,  having  been  approved 
by  Naval  Engineers.  All  the  machinery  and  devices  fitted  in  a  modern  Submarine 
Boat  are  shown,  and  to  make  the  engraving  more  readily  understood,  all  the  features 
are  shown  in  operative  form,  with  Officers  and  Men  in  the  act  of  performing  the  duties 
assigned  to  them  in  service  conditions.  This  CHART  IS  REALLY  AN  ENCYCLO- 
PEDIA OF  A  SUBMARINE 25  cents 

BOX  CAR  CHART. 

A  chart  showing  the  anatomy  of  a  box'car.  having  every  part  of  the  car  numbered  and 
its  proper  name  given  in  a  reference  list 25  cents 

GONDOLA  CAR  CHART. 

A  chart  showing  the  anatomy  of  a  gondola  car,  having  every  part  of  the  car  numbered 
and  its  proper  reference  name  given  in  a  reference  list 25  cents 

PASSENGER-CAR  CHART. 

A  chart  showing  the  anatomy  of  a  passenger-car,  having  every  part  of  the  car  numbered 
and  its  proper  name  given  in  a  reference  list 25  cents 

STEEL  HOPPER  BOTTOM  COAL  CAR. 

A  chart  showing  the  anatomy  of  a  steel  Hopper  Bottom  Coal  Car,  having  every  part 
of  the  car  numbered  and  its  proper  name  given  in  a  reference  list 25  cents 

TRACTIVE  POWER  CHART. 

A  chart  whereby  you  can  find  the  tractive  power  or  drawbar  pull  of  any  locomotive 
without  making  a  figure.  Shows  what  cylinders  are  equal,  how  driving  wheels  and 
steam  pressure  affect  the  power.  What  sized  engine  you  need  to  exert  a  given  drawbar 
pull  or  anything  you  desire  in  this  line 50  cents 

HORSE-POWER  CHART 

Shows  the  horse-power  of  any  stationary  engine  without  calculation.  No  matter  what 
the  cyh'nder  diameter  of  stroke,  the  steam  pressure  of  cut-off,  the  revolutions,  or 
whether  condensing  or  non-condensing,  it's  all  there.  Easy  to  use,  accurate,  and 
saves  time  and  calculations.  Especially  useful  to  engineers  and  designers.  50  cents 

BOILER  ROOM  CHART.    By  GEO.  L.  FOWLER. 

A  charts-size  14x28  inches — showing  in  isometric  perspective  the  mechanisms  be- 
longing in  a  modern  boiler  room.  The  various  parts  are  shown  broken  or  removed, 
so  that  the.  internal  construction  is  fully  illustrated.  Each  part  is  given  a  reference 
number,  and  these,  with  the  corresponding  name,  are  given  in  a  glossary  printed  at 
the  sides.  This  chart  is  really  a  dictionary  of  the  boiler  room — the  names  of  more  than 
200  parts  being  given 25  cents 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


COKE 

COKE— MODERN    COKING    PRACTICE,    INCLUDING    ANALYSIS     OF 
MATERIALS  AND  PRODUCTS.     By  J.  E.  CHRISTOPHER  and  T.  H.  BYROM. 

This,  the  standard  work  on  the  subject,  has  just  been  revised  and  is  now  issued  in 
two  volumes.  It  is  a  practical  work  for  those  engaged  in  Coke  manufacture  and 
the  recovery  [of  By-products.  Fully  illustrated  with  folding  plates.  It  has  been 
the  aim  of  the  authors,  in  preparing  this  book,  to  produce  one  which  shall  be  of  use 
and  benefit  to  those  who  are  associated  with,  or  interested  in,  the  modern  develop- 
ments of  the  industry.  Among  the  chapters  contained  in  Volume  I  are:  Introduc- 
tion. Classification  of  Fuels.  Impurities  of  Coals.  Coal  Washing.  Sampling 
and  Valuation  of  Coals,  etc.  Chlorific  Power  of  Fuels.  History  of  Coke  Manu- 
facture. Developments  in  Coke  Oven  Design;  Recent  Types  of  Coke  Ovens. 
Mechanical  Appliances  at  Coke.  Ovens.  Chemical  and  Physical  Examination  of 
Coke.  Volume  II  covers  By-p'roducts.  Each  volume  is  fully  illustrated,  with 
folding  plates.  Price,  per  volume $3.00 

COMPRESSED  AIR 

COMPRESSED  AIR  IN  ALL  ITS  APPLICATIONS.    By  GARDNER  D.  Hiscox. 

This  is  the  most  complete  book  on  the  subject  of  Air  that  has  ever  been  issued,  and  its 
thirty-five  chapters  include  about  every  phase  of  the  subject  one  can  think  of.  It  may 
be  called  an  encyclopedia  of  compressed  air.  It  is  written  by  an  expert,  who,  in  its 
665  pages,  has  dealt  with  the  subject  in  a  comprehensive  manner,  no  phase  of  it  being 
omitted.  Includes  the  physical  properties  of  air  from  a  vacuum  to  its  highest  pressure, 
its  thermodynamics,  compression,  transmission  and  uses  as  a  motive  power,  in  the 
Operation  of  Stationary'  and  Portable  Machinery,  in  Mining,  Air  Tools,  Air  Lifts, 
Pumping  of  Water,  Acids,  and  Oils;  the  Air  Blast  for  Cleaning  and  Painting,  the 
Sand  Blast  and  its  Work,  and  the  Numerous  Appliances  in  which  Compressed  Air  is 
a  Most  Convenient  and  Economical  Transmitter  of  Power  for  Mechanical  Work, 
Railway  Propulsion,  Refrigeration,  and  the  Various  Uses  to  which  Compressed  Air 
has  been  applied.  Includes  forty-four  tables  of  the  physical  properties  of  air,  its 
compression,  expansion,  and  volumes  required  for  various  kinds  of  work,  and  a  list 
of  patents  on  compressed  air  from  1875  to  date.  Over  500  illustrations,  5th  Edition, 
revised  and  enlarged.  Cloth  bound,  $6.00.  Half  Morocco,  price  ....  $7.50 

CONCRETE 


JUST  PUBLISHED— CONCRETE  WORKERS'  REFERENCE  BOOKS.  A 
SERIES  OF  POPULAR  HANDBOOKS  FOR  CONCRETE  USERS. 
Prepared  by  A.  A.  HOUGHTON Each  60  cents 

The  author,  in  preparing  this  Series,  has  not  only  treated  on  the  usual  types  of  construction, 
but  explains  and  illustrates  molds  and  systems  that  are  not  patented,  but  which  are  equal 
in  value  and  often  superior  to  those  restricted  by  patents.  These  molds  are  rery  easily  and 
cheaply  constructed  and  embody  simplicity,  rapidity  of  operation,  and  the  most  successful 
results  in  the  molded  concrete.  Each  of  these  Twelve  books  is  fully  illustrated,  and  the 
subjects  are  exhaustively  treated  in  plain  English. 

CONCRETE  WALL  FORMS.     By  A.  A.  HOUGHTON. 

A  new  automatic  wall  clamp  is  illustrated- with  working  drawings.     Other  types  of 

wall  forms,   clamps,   separators,   etc.,   are  also  illustrated  and  explained. 

(No.  1  of  Series) 60  cents 

CONCRETE  FLOORS  AND  SIDEWALKS.    By  A.  A.  HOUGHTON. 

The  molds  for  molding  squares,  hexagonal  and  many  other  styles  of  mosaic  floor  and 
sidewalk  blocks  are  fully  illustrated  and  explained.  (No.  2  of  Series)  .  .  60  cents 

PRACTICAL  CONCRETE  SILO  CONSTRUCTION.    By  A.  A.  HOUGHTON. 

Complete  working  drawings  and  specifications  are  given  for  several  styles  of  concrete 
silos,  with  illustrations  of  molds  for  monolithic  and  block  silos.  The  tables,  data,  and 
information  presented  in  this  book  are  of  the  utmost  value'in  planning  and  constructing 
all  forms  of  concrete  silos.  (No.  3  of  Series) 60  cents 

10 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 
MOLDING  CONCRETE  CHIMNEYS,  SLATE  AND  ROOF  TILES.    By  A.  A. 

HOUGHTON. 

The  manufacture  of  all  types  of  concrete  slate  and  roof  tile  Is  fully  treated.  Valuable 
data  on  all  forms  of  reinforced  concrete  roofs  are  contained  within  its  pages.  The 
construction  of  concrete  chimneys  by  block  and  monolithic  systems  is  fully  illustrated 
and  described.  A  number  of  ornamental  designs  of  chimney  construction  with  molds 
are  shown  in  this  valuable  treatise.  (No.  4  of  Series.) 60  cents 

MOLDING  AND  CURING  ORNAMENTAL  CONCRETE.    By  A.  A.  HOUGHTON. 

The  proper  proportions  of  cement  and  aggregates  for  various  finishes,  also  the  method 
of  thoroughly  mixing  and  placing  in  the  molds,  are  fully  treated.  An  exhaustive 
treatise  on  this  subject  that  every  concrete  worker  will  find  of  daily  use  and  value. 
(No.  5  of  Series.) 60  cents 

CONCRETE  MONUMENTS,  MAUSOLEUMS  AND  BURIAL  VAULTS.  By 
A.  A.  HOUGHTON. 

The  molding  of  concrete  monuments  to  imitate  the  most  expensive  cut  stone  is  ex- 
plained in  this  treatise,  with  working  drawings  of  easily  built  molds.  Cutting  in- 
scriptions and  designs  are  also  fully  treated.  (No.  6  of  Series.)  ...  60  cents 

MOLDING  CONCRETE  BATHTUBS,  AQUARIUMS  AND  NATATORIUMS. 
By  A.  A.  HOUGHTON. 

Simple  molds  and  instruction  are  given  for  molding  many  styles  of  concrete  bathtubs, 
swimming-pools,  etc.  These  molds  are  easily  built  and  permit  rapid  and  successful 
work.  (No.  7  of  Series.) 60  cents 

CONCRETE  BRIDGES,  CULVERTS  AND  SEWERS.  By  A.  A.  HOUGHTON. 
A  number  of  ornamental  concrete  bridges  with  illustrations  of  molds  are  given.  A 
collapsible  center  or  core  for  bridges,  culverts  and  sewers  is  fully  illustrated  with  de- 
tailed instructions  for  building.  (No.  8  of  Series.) 60  cents 

CONSTRUCTING  CONCRETE  PORCHES.    By  A.  A.  HOUGHTON. 

A  number  of  designs  with  working  drawings  of  molds  are  fully  explained  so  any  one 
can  easily  construct  different  styles  of  ornamental  concrete  porches  without  the  pur- 
chase of  expensive  molds.  (No.  9  of  Series.) 60  cents 

MOLDING  CONCRETE  FLOWER-POTS,  BOXES,  JARDINIERES,  ETC. 
By  A.  A.  HOUGHTON. 

The  molds  for  producing  many  original  designs  of  flower-pots,  urns,  flower-boxes, 
jardinieres,  etc.,  are  fully  illustrated  and  explained,  so  the  worker  can  easily  construct 
and  operate  same.  (No.  10  of  Series.) 60  cents 

MOLDING  CONCRETE  FOUNTAINS  AND  LAWN  ORNAMENTS.  By  A. 
A.  HOUGHTON. 

The  molding  of  a  number  of  designs  of  lawn  seats,  curbing,  hitching  posts,  pergolas,  sun 
dials  and  other  forms  of  ornamental  concrete  for  the  ornamentation  of  lawns  and  gar- 
dens, is  fully  illustrated  and  described.  (No.  11  of  Series) 60  cents 

CONCRETE  FROM  SAND  MOLDS.    By  A.  A.  HOUGHTON. 

A  Practical  Work  treating  on  a  process  which  has  heretofore  been  held  as  a  trade  secret 
by  the  few  who  possessed  it,  and  which  will  successfully  mold  every  and  any  class  of 
ornamental  concrete  work.  The  process  of  molding  concrete  with  sand  molds  is  of 
the  utmost  practical  value,  possessing  the  manifold  advantages  of  a  low  cost  of  molds, 
the  ease  and  rapidity  of  operation,  perfect  details  to  all  ornamental  designs,  density 
and  increased  strength  of  the  concrete,  perfect  curing  of  the  work  without  attention 
and  the  easy  removal  of  the  molds  regardless  of  any  undercutting  the  design  may  have. 
192  pages.  Fully  illustrated.  Price $2.00 

ORNAMENTAL  CONCRETE  WITHOUT  MOLDS.  By  A.  A.  HOUGHTON. 
The  process  for  making  ornamental  concrete  without  molds  has  lone  been  held  as  a 
secret,  and  now,  for  the  first  time,  this  process  is  given  to  the  public.  The  book 
reveals  the  secret  and  is  the  only  book  published  which  explains  a  simple,  practical 
method  whereby  the  concrete  worker  is  enabled,  by  employing  wood  and  metal  tem- 
plates of  different  designs,  to  mold  or  model  in  concrete  any  Cornice,  Archivolt, 
Column,  Pedestal,  Base  Cap,  Urn  or  Pier  in  a  monolithic  form — right  upon  the  job. 
These  may  be  molded  in  units  or  blocks,  and  then  built  up  to  suit  the  specifications 
demanded.  This  work  is  fully  illustrated,  with  detailed  engravings.  Price  .  $2.0O 

II 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

CONCRETE    FOR    THE   FARM    AND    IN    THE    SHOP.     BY    H.    COLIN 
CAMPBELL,  C.E.,  E.M. 

"Concrete  for  the  Farm  and  In  the  Shop"  is  a  new  book  from  cover  to  cover,  illustrat- 
ing and  describing  in  plain,  simple  language  many  of  the  numerous  applications  of 
concrete  within  the  range  of  the  home  worker.  Among  the  subjects  treated  are: 
Principles  of  reinforcing;  methods  of  protecting  concrete  so  as  to  insure  proper  harden- 
ing; home-made  mixers;  mixing  by  hand  and  machine;  form  construction,  described 
and  illustrated  by  drawings  and  photographs;  construction  of  concrete  walls  and 
fences;  concrete  fence  posts;  concrete  gate  posts;  corner  posts;  clothes  line  posts; 
grape  arbor  posts;  tanks;  troughs;  cisterns;  hog  wallows;  feeding  floors  and  barn- 
yard pavements ;  foundations ;  well  curbs  and  platforms ;  indoor  floors ;  sidewalks ;  steps ; 
concrete  hotbeds  and  cold  frames;  concrete  slab  roofs;  walls  far  buildings;  repairing 
leaks  in  tanks  and  cisterns;  and  all  topics  associated  with  th^s1  subjects  as  bearing 
upon  securing  the  best  results  from  concrete  are  dwelt  upon  atsuffici  >nt  1  ngth  in  plain 
every-day  English  so  that  the  inexperienced  person  desiring  to  und  rtaka  a  piece  of 
concrete  construction  can,  by  following  the  directions  set  forth  in  this  book,  secute  10O 
per  cent  success  every  time.  A  number  of  convenient  and  practical  tubl  -s  for  estimating 
quantities,  and  some  practical  examples,  are  also  given.  (5x7).  149  pages,  51  il- 
lustrations. Price $1.OO 

POPULAR  HANDBOOK  FOR  CEMENT  AND  CONCRETE  USERS.  By 

MYRON  H.  LEWIS. 

This  is  a  concise  treatise  of  the  principles  and  methods  employed  in  the  manufacture 
and  use  of  cement  in  all  classes  of  modern  works.  The  author  has  brought  together 
in  this  work  all  the  salient  matter  of  interest  to  the  user  of  concrete  and  its  many 
diversified  products.  The  matter  is  presented  in  logical  and  systematic  order,  clearly 
written,  fully  illustrated  and  free  from  involved  mathematics.  Everything  of  value  to 
the  concrete  user  is  given,  including  kinds  of  cement  employed  in  construction,  concrete 
architecture,  inspection  and  testing,  waterproofing,  coloring  and  painting,  rules,  tables, 
working  and  cost  data.  The  book  comprises  thirty-three  chapters,  as  follows: 
Introductory.  Kinds  of  Cements  and  How  They  are  Made.  Properties.  Testing 
and  Requirements  of  Hydraulic  Cement.  Concrete  and  its  Properties.  Sand,  Broken 
Stone  and  Gravel  for  Concrete.  How  to  Proportion  the  Materials.  How  to  Mix 
and  Place  Concrete.  Forms  of  Concrete  Construction.  The  Architectural  and  Artistic 
Possibilities  of  Concrete.  Concrete  Residences.  Mortars,  Plasters  and  Stucco,  and 
How  to  Use  them.  The  Artistic  Treatment  of  Concrete  Surfaces.  Concrete  Building 
Blocks.  The  Making  of  Ornamental  Concrete.  Concrete  Pipes,  Fences,  Posts,  etc. 
Essential  Features  and  Advantages  of  Reenforced  Concrete.  How  to  Design  Reen- 
forced  Concrete  Beams,  Slabs  and  Columns.  Explanations  of  the  Methods  and 
Principles  in  Designing  Reenforced  Concrete  Beams  and  Slabs.  Systems  of  Reen- 
forcement  Employed.  Reenforced  Concrete  in  Factory  and  General  Building  Con- 
struction. Concrete  in  Foundation  Work.  Concrete  Retaining  Walls,  Abutments 
and  Bulkheads.  Concrete  Arches  and  Arch  Bridges.  Concrete  Beam  and  Girder 
Bridges.  Concrete  in  Sewerage  and  Drainage  Works.  Concrete  Tanks,  Dams  and 
Reservoirs.  Concrete  Sidewalks,  Curbs  and  Pavements.  Concrete  in  Railroad  Con- 
»  structions.  The  Utility  of  Concrete  on  the  Farm.  The  Waterproofing  of  Concrete 
Structure.  Grout  of  Liquid  Concrete  and  Its  Use.  Inspection  of  Concrete  Work.  Cost 
of  Concrete  Work.  Some  of  the  special  features  of  the  book  are:  1.  The  Attention 
Paid  to  the  Artistic  and  Architectural  Side  of  Concrete  Work.  2.  The  Authoritative 
Treatment  of  the  Problem  of  Waterproofing  Concrete.  3.  An  Excellent  Summary  of 
the  Rules  to  be  Followed  in  Concrete  Construction.  4.  The  Valuable  Cost  Data  and 
Useful  Tables  given.  A  valuable  Addition  to  the  Library  of  Every  Cement  and 
Concrete  User.  Price $3.00 

WHAT    IS    SAID    OF    THIS    BOOK: 

"The  field  of  Concrete  Construction  is  well  covered  and  the  matter  contained  is  well 
within  the  understanding  of  any  person." — Engineering-Contracting. 
"  Should  be  on  the  bookshelves  of  every  contractor,  engineer,  and  architect  in  the 
land."— National  Builder. 

WATERPROOFING  CONCRETE.    By  MYRON  H.  LEWIS. 

Modern  Methods  of  Waterproofing  Concrete  and  Other  Structures.  A  condensed 
statement  of  the  Principles,  Rules,  and  Precautions  to  be  Observed  in  Waterproofing 
and  Dampproofing  Structures  and  Structural  Materials.  Paper  binding.  Illustrated. 
Price 60  cents 

DICTIONARIES 

STANDARD  ELECTRICAL  DICTIONARY.    By  T.  O'CoNOR  SLOANE. 

An  indispensable  work  to  all  interested  in  electrical  science.  Suitable  alike  for  the 
student  and  professional.  A  practical  handbook  of  reference  containing  definitions  of 
about  5000  distinct  words,  terms  and  phrases.  The  definitions  are  terse  and  concise 

12 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

and  include  every  term  used  in  electrical  science.  Recently  issued.  An  entirely  new 
edition.  Should  be  in  the  possession  of  all  who  desire  to  keep  abreast  with  the  progress 
of  this  branch  of  science.  Complete,  concise  and  convenient.  682  pages.  393  illustra- 
tions. Price $3.00 

AVIATION  TERMS— ENGLISH-FRENCH;  FRENCH-ENGLISH.  By  MAJOR 
VICTOR  W.  PAGE,  A.S.,  S.C.U.S.R.,  and  LIEUT.  PAUL  MONTARIOL  of  the 
French  Flying  Corps. 

A-  complete  glossary  of  practically  all  terms  used  in  aviation,  having  lists  in  both 
French  and  English  with  equivalents  in  either  language.  Include  all  words  in 
common  use.  A  complete,  well  illustrated  volume  intended  to  facilitate  conversa- 
tion between  English-speaking  and  French  aviators.  The  lists  are  confined  to  essen- 
tials, and  special  folding  plates  are  included  to  show  all  important  airplane  parts. 
The  lists  are  divided  into  four  sections:  1.  Flying  Field  Terms.  2.  The  Airplane. 
3.  The  Engine.  4.  Tools  and  Shop  Terms.  Should  be  in  every  aviator's  and 
mechanic's  kit.  Price Sl.OO 

DIES— METAL  WORK 

DIES:  THEIR  CONSTRUCTION  AND  USE  FOR  THE  MODERN  WORKING 
OF  SHEET  METALS.  By  J.  V.  WOODWORTH. 

A  most  useful  book,  and  one  which  should  be  in  the  hands  of  all  engaged  in  the  presa 
working  of  metals;  treating  on  the  Designing,  Constructing,  and  Use  of  Tools,  Fixtures 
and  Devices,  together  with  the  manner  in  which  they  should  be  used  in  the  Powr 
Press,  for  the  cheap  and  rapid  production  of  the  great  variety  of  sheet-metal  articles 
now  in  use.  It  is  designed  as  a  guide  to  the  production  of  sheet-metal  parts  at  the 
minimum  of  cost  with  the  maximum  of  output.  The  hardening  and  tempering  of 
Press  tools  and  the  classes  of  work  which  may  be  produced  to  the  best  advantage  by 
the  use  of  dies  in  the  power  press  are  fully  treated.  Its  505  illustrations  show  dies, 
press  fixtures  and  sheet-metal  working  devices,  the  descriptions  of  which  are  so  clear  and 
practical  that  all  metal-working  mechanics  will  be  able  to  understand  how  to  design, 
construct  and  use  them.  Many  of  the  dies  and  press  fixtures  treated  were  either 
constructed  by  the  author  or  under  his  supervision.  Others  were  built  by  skilful 
'  mechanics  and  are  in  use  in  large  sheet-metal  establishments  and  machine  shops. 
5th  Edition.  Price $3.50 

PUNCHES,  DIES  AND  TOOLS  FOR  MANUFACTURING  IN  PRESSES.  By 
J.  V.  WOODWORTH. 

This  work  is  a  companion  volume  to  the  author's  elementary  work  entitled  "Dies,  Their 
Construction  and  Use."  It  does  not  go  into  the  details  of  die-making  to  the  extent  of 
the  author's  previous  book,  but  gives  a  comprehensive  review  of  the  field  of  operations 
carried  on  by  presses.  A  large  part  of  the  information  given  has  been  drawn  from  the 
author's  personal  experience.  It  might  well  be  termed  an  Encyclopedia  of  Die-Making, 
Punch-Making,  Die-Sinking,  Sheet-Metal  Working,  and  Making  of  Special  Tools,  Sub- 
presses,  Devices  and  Mechanical  Combinations  for  Punching,  Cutting,  Bending,  Form- 
ing, Piercing,  Drawing,  Compressing  and  Assembling  Sheet-Metal  Parts,  and  also  Arti- 
cles of  other  Materials  in  Machine  Tools.  2d  Edition.  Price $4.50 

DROP  FORGING,  DIE-SINKING  AND  MACHINE-FORMING  OF  STEEL. 
By  J.  V.  WOODWORTH. 

This  is  a  practical  treatise  on  Modern  Shop  Practice,  Processes,  Methods,  Machine 
Tools,  and  Details  treating  on  the  Hot  and  Cold  Machine-Forming  of  Steel  and  Iron 
into  Finished  Shapes;  together  with  Tools,  Dies,  and  Machinery  involved  in  the 
manufacture  of  Duplicate  Forgings  and  Interchangeable  Hot  and  Cold  Pressed  Parts 
from  Bar  and  Sheet  Metal.  This  book  fills  a  demand  of  long  standing  for  information 
regarding  drop-forgings,  die-sinking  and  machine-forming  of  steel  and  the  shop 
practice  involved,  as  it  actually  exists  in  the  modern  drop-forging  shop.  The  processes 
of  die-sinking  and  force-making,  which  are  thoroughly  described  and  illustrated  in  this 
admirable  work,  are  rarely  to  be  found  explained  in  such  a  clear  and  concise  manner 
as  is  here  set  forth.  The  process  of  die-sinking  relates  to  the  engraving  or  sinking  of 
the  female  or  lower  dies,  such  as  are  used  for  drop-forgings,  hot  and  cold  machine 
forging,  swedging  and  the  press  working  of  metals.  The  process  of  force-making 
relates  to  the  engraving  or  raising  of  the  male  or  upper  dies  used  in  producing  the 
lower  dies  for  the  press-forming  and  machine-forging  of  duplicate  parts  of  metal. 
In  addition  to  the  arts  above  mentioned  the  book  contains  explicit  information  re- 
garding the  drop-forging  and  hardening  plants,  designs,  conditions,  equipment,  drop 
hammers,  forging  machines,  etc.,  machine  forging,  hydraulic  forging,  autogenous 
welding  and  shop  practice.  The  book  contains  eleven  chapters,  and  the  information 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

contained  in  these  chapters  is  just  what  will  prove  most  valuable  to  the  forged-metal 
worker.  All  operations  described  in  the  work  are  thoroughly  illustrated  by  means  of 
perspective  half-tones  and  outline  sketches  of  the  machinery  employed.  300  detailed 
Illustrations.  LPrice $3.0O 

DRAWING— SKETCHING  PAPER 

PRACTICAL  PERSPECTIVE.     By  RICHARDS  and  COLVIN. 

Shows  just  how  to  make  all  kinds  of  mechanical  drawings  in  the  only  practical  per- 
spective isometric.  Makes  everything  plain  so  that  any  mechanic  can  understand 
a  sketch  or  drawing  in  this  way.  Saves  time  in  the  drawing  room,  and  mistakes  in  the 
shops.  Contains  practical  examples  of  various  classes  of  work.  4th  Edition.  60  cents 

LINEAR  PERSPECTIVE  SELF-TAUGHT.    By  HERMAN  T.  C.  KRAUS. 

This  work  gives  the  theory  and  practice  of  linear  perspective,  as  used  in  architectural, 
engineering  and  mechanical  drawings.  Persons  taking  up  the  study  of  the  subject 
by  themselves  will  be  able,  by  the  use  of  the  instruction  given,  to  readily  grasp  the 
subject,  and  by  reasonable  practice  become  good  perspective  draftsmen.  The  arrange- 
ment of  the  book  is  good;  the  plate  is  on  the  left-hand,  while  the  descriptive  text 
follows  on  the  opposite  page,  so  as  to  be  readily  referred  to.  The  drawings  are  on 
sufficiently  large  scale  to  show  the  work  clearly  and  are  plainly  figured.  There  is 
included  a  self-explanatory  chart  which  gives  all  information  necessary  for  the  thorough 
understanding  of  perspective.  This  chart  alone  is  worth  many  times  over  the  price  of 
the  book.  2d  Revised  and  enlarged  Edition $2.5O 

SELF-TAUGHT  MECHANICAL  DRAWING  AND  ELEMENTARY  MACHINE 
DESIGN.  By  F.  L.  SYLVESTER,  M.E.,  Draftsman,  with  additions  by  ERIK 
OBERG,  associate  editor  of  "Machinery." 

This  is  a  practical  treatise  on  Mechanical  Drawing  and  Machine  Design,  comprising 
the  first  principles  of  geometric  and  mechanical  drawing,  workshop  mathematics, 
mechanics,  strength  of  materials  and  the  calculations  and  design  of  machine  details. 
The  author's  aim  has  been  to  adapt  this  treatise  to  the  requirements  of  the  practical 
mechanic  and  young  draftsman  and  to  present  the  matter  in  as  clear  and  concise  a 
manner  as  possible.  To  meet  the  demands  of  this  class  of  students,  practically  all  the 
important  elements  of  machine  design  have  been  dealt  with,  and  in  addition  algebraic 
formulas  have  been  explained,  and  the  elements  of  trigonometry  treated  in  the  manner 
best  suited  to  the  needs  of  the  practical  man.  The  book  is  divided  into  20  chapters, 
and  in  arranging  the  material,  mechanical  drawing,  pure  and  simple,  has  been  taken 
up  first,  as  a  thorough  understanding  of  the  principles  of  representing  objects  facilitates 
the  further  study  of  mechanical  subjects.  This  is  followed  by  the  mathematics  neces- 
sary for  the  solution  of  the  problems  in  machine  design  which  are  presented  later,  and 
a  practical  introduction  to  theoretical  mechanics  and  the  strength  of  materials.  The 
various  elements  entering  into  machine  design,  such  as  cams,  gears,  sprocket-wheels, 
cone  pulleys,  bolts,  screws,  couplings,  clutches,  shafting  and  fly-wheels,  have  been 
treated  in  such  a  way  as  to  make  possible  the  use  of  the  work  as  a  text-book  for  a 
continuous  course  of  study.  It  is  easily  comprehended  and  assimilated  even  by 
students  of  limited  previous  training.  330  pages,  2 15  engravings.  Price  .  .  $2.50 

A  NEW  SKETCHING  PAPER. 

A  new  specially  ruled  paper  to  enable  you  to  make  sketches  or  drawings  in  isometric 
perspective  without  any  figuring  or  fussing.  It  is  being  used  for  shop  details  as  well 
as  for  assembly  drawings,  as  it  makes  one  sketch  do  the  work  of  three,  and  no  workman 
can  help  seeing  just  what  is  wanted.  Pads  of  40  sheets,  6x9  inches,  25  cents.  Pads 
of  40  sheets.  9x12  inches,  50  cents;  40  sheets,  12x18,  Price $1.00 

ELECTRICITY 

ARITHMETIC  OF  ELECTRICITY.    By  Prof.  T.  O'CoNOR  SLOANE. 

A  practical  treatise  on  electrical  calculations  of  all  kinds  reduced  to  a  series  of  rules,  all 
of  the  simplest  forms,  and  involving  only  ordinary  arithmetic;  each  rule  illustrated 
by  one  or  more  practical  problems,  with  detailed  solution  of  each  one.  This  book  is 
classed  among  the  most  useful  works  published  on  the  science  of  electricity,  covering 
as  it  does  the  mathematics  of  electricity  in  a  manner  that  will  attract  the  attention 
of  those  who  are  not  familiar  with  algebraical  formulas.  20th  Edition.  160  pages. 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

COMMUTATOR  CONSTRUCTION.    By  WM.  BAXTER,  JR. 

The  business  end  of  any  dynamo  or  motor  of  the  direct  current  type  is  the  commutator. 
This  book  goes  into  the  designing,  building,  and  maintenance  of  commutators,  showa 
how  to  locate  troubles  and  how  to  remedy  them;  everyone  who  fusses  with  dynamos 
needs  this.  4th  Edition 35  cents 

DYNAMO  BUILDING  FOR  AMATEURS,  OR  HOW  TO  CONSTRUCT  A 
FIFTY- WATT  DYNAMO.  By  ARTHUR  J.  WEED,  Member  of  N.  Y.  Electrical 
Society. 

A  practical  treatise  showing  in  detail  the  construction  of  a  small  dynamo  or  motor,  the 
entire  machine  work  of  which  can  be  done  on  a  small  foot  lathe.  Dimensioned  working 
drawings  are  given  for  each  piece  of  machine  work,  and  each  operation  is  clearly 
described.  This  machine,  when  used  as  a  dynamo,  has  an  output  of  fifty  watts;  when 
used  as  a  motor  it  will  drive  a  small  drill  press  or  lathe.  It  can  be  used  to  drive  a 
sewing  machine  on  any  and  all  ordinary  work.  The  book  is  illustrated  with  more 
than  sixty  original  engravings  showing  the  actual  construction  of  the  different  parts. 
Among  the  contents  are  chapters  on:  1.  Fifty-Watt  Dynamo.  2.  Side  Bearing 
Rods.  3.  Field  Punching.  4.  Bearings.  5.  Commutator.  6.  Pulley.  7.  Brush 
Holders.  8.  Connection  Board.  9.  Armature  Shaft.  10.  Armature.  11.  Armature 
Winding.  12.  Field  Winding.  13.  Connecting  and  Starting.  Price,  cloth,  $1.0O 

ELECTRIC  WIRING,  DIAGRAMS  AND  SWITCHBOARDS.  By  NEWTON 
HARRISON. 

A  thoroughly  practical  treatise  covering  the  subject  of  Electric  Wiring  in  all  its  branches,  ' 
including  explanations  and  diagrams  which  are  thoroughly  explicit  and  greatly  simplify 
the  subject.  Practical,  every-day  problems  in  wiring  are  presented  and  the  method 
of  obtaining  intelligent  results  clearly  shown.  Only  arithmetic  is  used.  Ohm's  law 
is  given  a  simple  explanation  with  reference  to  wiring  for  direct  and  alternating 
currents.  The  fundamental  principle  of  drop  of  potential  in  circuits  is  shown  with  its 
various  applications.  The  simple  circuit  is  developed  with  the  position  of  mains, 
feeders  and  branches;  their  treatment  as  a  part  of  a  wiring  plan  and  their  employ- 
ment in  house  wiring  clearly  illustrated.  Some  simple  facts  about  testing  are  included 
in  connection  with  the  wiring.  Molding  and  conduit  work  are  given  careful  considera- 
tion; and  switchboards  are  systematically  treated,  built  up  and  illustrated,  showing 
the  purpose  they  serve,  for  connection  with  the  circuits,  and  to  shunt  and  compound 
wound  machines.  The  simple  principles  of  switchboard  construction,  the  develop- 
ment of  the  switchboard,  the  connections  of  the  various  instruments,  including  the 
lightning  arrester,  are  also  plainly  set  forth. 

Alternating  current  wiring  is  treated,  with  explanations  of  the  power  factor,  conditions 
calling  for  various  sizes  of  wire,  and  a  simple  way  of  obtaining  the  sizes  for  single-phase, 
two-phase  and  three-phase  circuits.  This  is  the  only  complete  work  issued  showing 
and  telling  you  what  you  should  know  about  direct  and  alternating  current  wiring.  It 
is  a  ready  reference.  The  work  is  free  from  advanced  technicalities  and  mathematics, 
arithmetic  being  used  throughout.  It  is  in  every  respect  a  handy,  well-written, 
instructive,  comprehensive  volume  on  wiring  for  the  wireman,  foreman,  contractor, 
or  electrician.  272  pages;  105  illustrations.  Price $2.0O 

ELECTRIC  FURNACES  AND  THEIR  INDUSTRIAL  APPLICATIONS.  By 
J.  WRIGHT. 

This  is  a  book  which  will  prove  of  interest  to  many  classes  of  people:  the  manufacturer 
•who  desires  to  know  what  product  can  be  manufactured  successfully  in  the  electric 
furnace,  the]  chemist  who  wishes  to  post  himself  on  electro  -  chemistry,  and  the 
student  of  science  who  merely  looks  into  the  subject  from  curiosity.  New  revised 
and  enlarged  edition.  320  pages.  Fully  illustrated.  Cloth.  Price  .  .  $3.50 

ELECTRIC  TOY  MAKING,  DYNAMO  BUILDING,  AND  ELECTRIC  MOTOR 
CONSTRUCTION.  By  Prof.  T.  O'CoNOR  SLOANE. 

This  work  treats  of  the  making  at  home  of  electrical  toys,  electrical  apparatus,  motors, 
dynamos  and  instruments  in  general,  and  is  designed  to  bring  within  the  reach  of 
young  and  old  the  manufacture  of  genuine  and  useful  electrical  appliances.  The  work 
is  especially  designed  for  amateurs  and  young  folks. 

Thousands  of  our  young  people  are  daily  experimenting,  and  busily  engaged  in  making 
electrical  toys  and  apparatus  of  various  kinds.  The  present  work  is  just  what  is  want- 
ed to  give  the  much  needed  information  in  a  plain,practical  manner,  with  illustrations 
to  make  easy  the  carrying  out  of  the  work.  20th  Edition.  Price  ....  $1.00 

PRACTICAL  ELECTRICITY.    By  Prof.  T.  O'CONOR  SLOANE. 

This  work  of  768  pages  was  previously  known  as  Sloane's  Electricians'  Hand  Book,  and 
is  intended  for  the  practical  electrician  who  has  to  make  things  go.  The  entire 

15 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

field  of  electricity  is  covered  within  its  pages.  Among  some  of  the  subjects  treated 
are:  The  Theory  of  the  Electric  Current  and  Circuit,  Electro-Chemistry,  Primary 
Batteries,  Storage  Batteries,  Generation  and  Utilization  of  Electric  Powers,  Alter- 
nating Current,  Armature  Winding,  Dynamos  and  Motors,  Motor  Generators. 
Operation  of  the  Central  Station  Switchboards,  Safety  Appliances,  Distribution 
of  Electric  Light  and  Power,  Street  Mains,  Transformers,  Arc  and  Incandescent 
Lighting,  Electric  Measurements,  Photometry,  Electric  Rtulways,  Telephony,  Bell- 
Wiring,  Electric-Plating,  Electric  Heating,  Wireless  Telegraphy,  etc.  It  contains  no 
useless  theory;  everything  is  to  the  point.  It  teaches  you  just  what  you  want  to 
know  about  electricity.  It  is  the  standard  work  published  on  the  subject.  Forty- 
one  chapters,  556  engravings.  Price $3.50 

ELECTRICITY  SIMPLIFIED.     By  Prof.  T.  O'CoNOR  SLOANE. 

The  object  of  "Electricity  Simplified"  is  to  make  the  subject  as  plain  as  possible  and 
to  show  what  the  modern  conception  of  electricity  is;  to  show  how  two  plates  of 
different  metal,  immersed  in  acid,  can  send  a  message  around  the  globe;  to  explain 
how  a  bundle  of  copper  wire  rotated  by  a  steam  engine  can  be  the  agent  in  lighting 
our  streets,  to  tell  what  the  volt,  ohm  and  ampere  are,  and  what  high  and  low  tension 
mean;  and  to  answer  the  questions  that  perpetually  arise  in  the  mind  in  this  age  of 
electricity.  13th  Edition.  172  pages.  Illustrated.  Price $1.00 

HOUSE  WIRING.     By  THOMAS  W.  POPPE. 

This  work  describes  and  illustrates  the  actual  installation  of  Electric  Light  Wiring, 
the  manner  in  which  the  work  should  be  done,  and  the  method  of  doing  it.  The  book 
can  be  conveniently  carried  in  the  pocket.  It  is  intended  for  the  Electrician,  Helper 
and  Apprentice.  It  solves  all  Wiring  Problems  and  contains  nothing  that  conflicts 
with  the  rulings  of  the  National  Board  of  Fire  Underwriters.  It  gives  just  the  informa- 
tion essential  to  the  Successful  Wiring  of  a  Building.  Among  the  subjects  treated  are: 
Locating  the  Meter.  Panel  Boards.  Switches.  Plug  Receptacles.  Brackets.  Ceiling 
Fixtures.  The  Meter  Connections.  The  Feed  Wires.  The  Steel  Armored  Cable 
System.  The  Flexible  Steel  Conduit  System.  The  Ridig  Conduit  System.  A  digest 
of  the  National  Board  of  Fire  Underwriters'  rules  relating  to  metallic  wiring  systems. 
Various  switching  arrangements  explained  and  diagrammed.  The  easiest  method  of 
testing  the  Three-  and  Four-way  circuits  explained.  The  grounding  of  all  metallic 
wiring  systems  and  the  reason  for  doing  so  shown  and  explained.  The  insulation  of 
the  metal  parts  of  lamp  fixtures  and  the  reason  for  the  same  described  and  illustrated. 
125  pages.  2nd  Edition,  revised  and  enlarged.  Fully  illustrated.  Flexible  cloth. 
Price 60  cents 

WHAT    IS    SAID    OF   THIS    BOOK: 

"  The  information  given  is  exact  and  exhaustive  without  being  too  technical  or  over- 
laden with  details."— Druggists'  Circular. 

HOW  TO  BECOME  A  SUCCESSFUL  ELECTRICIAN.     By  Prof.  T.  O'CoNOH 
SLOANE. 

Every  young  man  who  wishes  to  become  a  successful  electrician  should  read  this  book. 
It  tells  in  simple  language  the  surest  and  easiest  way  to  become  a  successful  electrician. 
The  studies  to  be  followed,  methods  of  work,  field  of  operation  and  the  requirements 
of  the  successful  electrician  are  pointed  out  and  fully  explained.  Every  young  en- 
gineer will  find  this  an  excellent  stepping  stone  to  more  advanced  works  on  electricity 
which  he  must  master  before  success  can  be  attained.  Many  young  men  become  dis- 
couraged at  the  very  outstart  by  attempting  to  read  and  study  books  that  are  far 
beyond  their  comprehension.  This  book  serves  as  the  connecting  link  between  the 
rudiments  taught  hi  the  public  schools  and  the  real  study  of  electricity.  It  is  inter- 
esting from  cover  to  cover.  Eighteenth  Revised  Edition,  just  issued.  205  pages. 
Illustrated.  Price $1.00 

STANDARD  ELECTRICAL  DICTIONARY.    By  T.  O'CONOR  SLOANE. 

An  indispensable  work  to  all  interested  in  electrical  science.  Suitable  alike  for  the 
student  and  professional.  A  practical  handbook  of  reference  containing  definitions 
of  about  5,000  distinct  words,  terms  and  phrases.  The  definitions  are  terse  and 
concise  and  include  every  term  used  in  electrical  science.  Recently  issued.  An  en- 
tirely new  edition.  Should  be  in  the  possession  of  all  who  desire  to  keep  abreast  with 
the  progress  of  this  branch  of  science.  In  its  arrangement  and  typography  the  book 
is  very  convenient.  The  word  or  term  defined  is  printed  in  black-faced  type  which 
readily  catches  the  eye,  while  the  body  of  the  page  is  in  smaller  but  distinct  type.  The 
definitions  are  well  worded,  and  so  as  to  be  understood  by  the  non-technical  reader. 
The  general  plan  seems  to  be  to  give  an  exact,  concise  definition,  and  then  amplify 
and  explain  in  a  more  popular  way.  Synonyms  are  also  given,  and  references  to  other 
words  and  phrases  are  made.  A  very  complete  and  accurate  index  of  fifty  pages  is 
at  the  end  of  the  volume;  and  as  this  index  contains  all  synonyms,  and  as  all  phrases 

j6 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 


are  indexed  in  every  reasonable  combination  of  words,  reference  to  the  proper  place 
in  the  body  of  the  book  is  readily  made.  It  is  dimcult  to  decide  how  far  a  book  of 
this  character  is  to  keep  the  dictionary  form,  and  to  what  extent  it  may  assume  the 
encyclopedia  form.  For  some  purposes,  concise,  exactly  worded  definitions  are  needed ; 
for  other  purposes,  more  extended  descriptions  are  required.  This  book  seeks  to  satisfy 
both  demands,  and  does  it  with  considerable  success.  Complete,  concise  and  con- 
venient. 682  pages.  393  illustrations.  Twelfth  Edition.  Price  ....  $3.00 

SWITCHBOARDS.    By  WILLIAM  BAXTER,  JR. 

This  book  appeals  to  every  engineer  and  electrician  who  wants  to  knew  the  practical 
side  of  things.  It  takes  up  all  sorts  and  conditions  of  dynamos,  connections  and 
circuits,  and  shows  by  diagram  and  illustration  just  how  the  switchboard  should  be 
connected.  Includes  direct  and  alternating  current  boards,  also  those  for  arc  lighting, 
incandescent  and  power  circuits.  Special  treatment  on  high  voltage  boards  for  power 
transmission.  2d  Edition.  19O  pages.  Illustrated.  Price $2.00 

TELEPHONE   CONSTRUCTION,   INSTALLATION,  WIRING,   OPERATION 
AND  MAINTENANCE.     By  W.  H.  RADCLIFFE  and  H.  C.  GUSHING. 

This  book  is  intended  for  the  amateur,  the  wireman,  or  the  engineer  who  desires  to 
establish  a  means  of  telephonic  communication  between  the  rooms  of  his  home,  office, 
or  shop.  It  deals  only  with  such  things  as  may  be  of  use  to  him  rather  than  with 
theories. 

Gives  the  principles  of  construction  and  operation  of  both  the  Bell  and  Independent 
instruments :  approved  methods  of  installing  and  wiring  them ;  the  means  of  protecting 
them  from  lightning  and  abnormal  currents;  their  connection  together  for  operation 
as  series  or  bridging  stations ;  and  rules  for  their  inspection  and  maintenance.  Line 
wiring  and  the  wiring  and  operation  of  special  telephone  systems  are  also  treated. 
Intricate  mathematics  are  avoided,  and  all  apparatus,  circuits  and  systems  are  thor- 
oughly described.  The  appendix  contains  definitions  of  units  and  terms  used  in  the 
text.  Selected  wiring  tables,  which  are  very  helpful,  are  also  included.  Among  the 
subjects  treated  are  Construction,  Operation,  and  Installation  of  Telephone  Instru- 
ments; Inspection  and  Maintenance  of  Telephone  Instruments;  Telephone  Line 
Wiring;  Testing  Telephone  Line  Wires  and  Cables ;  Wiring  and  Operation  of  Special 
Telephone  Systems,  etc.  2nd  Edition,  revised  and  enlarged.  223  pages.  154 
illustrations $1.25 

WIRELESS  TELEGRAPHY  AND  TELEPHONY  SIMPLY  EXPLAINED.    By 
ALFRED  P.  MORGAN. 

This  is  undoubtedly  one  of  the  most  complete  and  comprehensible  treatises  on  the 
subject  ever  published,  and  a  close  study  of  its  pages  will  enable  one  to  master  all  the 
details  of  the  wireless  transmission  of  messages.  The  author  has  filled  a  long-felt 
want  and  has  succeeded  in  furnishing  a  lucid,  comprehensible  explanation  in  simple 
language  of  the  theory  and  practice  of  wireless  telegraphy  and  telephony. 
Among  the  contents  are:  Introductory;  Wireless  Transmission  and  Reception — The 
Aerial  System,  Earth  Connections — The  Transmitting  Apparatus,  Spark  Coils  and 
Transformers;  Condensers,  Helixes,  Spark  Gaps,  Anchor  Gaps,  Aerial  Switches — The 
Receiving  Apparatus,  Detectors,  etc. — Tuning  and  Coupling,  Tuning  Coils,  Loose 
Couplers,  Variable  Condensers,  Directive  Wave  Systems — Miscellaneous  Apparatus, 
Telephone  Receivers,  Range  of  Stations,  Static  Interference— Wireless  Telephones, 
Sound  and  Sound  Waves, The  Vocal  Cords  and  Ear — Wireless  Telephone,  How  Sounds 
Are  Changed  into  Electric  Waves — Wireless  Telephones,  The  Apparatus — Summary. 
154  pages.  156  engravings.  Price $1.25 

WHAT    IS    SAID    OF    THIS    BOOK: 
"This  book  should  be  in  both  the  home  and  school  library." — The  Youths'  Instructor. 

WIRING  A  HOUSE.    By  HERBERT  PRATT. 

Shows  a  house  already  built;  tells  just  how  to  start  about  wiring  it;  where  to  begin; 
what  wire  to  use;  how  to  run  it  according  to  Insurance  Rules;  in  fact,  just  the  informa- 
tion you  need.  Directions  apply  equally  to  a  shop.  Fourth  edition  .  .  35  cents 

RADIO  TIME  SIGNAL  RECEIVER.    By  AUSTIN  C.  LESCARBOURA. 

This  new  book,  "A  Radio  Time  Signal  Receiver,"  tells  you  how  to  build  a  simple 
outfit  designed  expressly  for  the  beginner.  You  can  build  the  outfits  ii>  your  own 
workshop  and  install  them  for  jewelers  either  on  a  one-payment  or  a  rental  basis. 
The  apparatus  is  of  such  simple  design  that  it  may  be  made  by  the  average  amateur 
mechanic  possessing  a  few  ordinary  tools.  42  pages.  Paper.  Price  .  .  35  cents 

17 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 


CONSTRUCTION  OF  A  TRANSATLANTIC  WIRELESS  RECEIVING  SET. 
By  L.  G.  PACENT  and  T.  S.  CURTIS. 

A  work  for  the  Radio  student  who  desires  to  construct  and  operate  apparatus  that 
will  permit  of  the  reception  of  messages  from  the  large  stations  in  Europe  with  an 
aerial  .of  amateur  proportions.  36  pages.  23  illustrations,  cloth.  Price  .  35  cents 

ELECTRIC  BELLS.    By  M.  B.  SLEEPER. 

A  complete  treatise  for  the  practical  worker  in  installing,  operating,  and  testing 
bell  circuits,  burglar  alarms,  thermostats,  and  other  apparatus  used  with  electric 
bells.  Both  the  electrician  and  the  experimenter  will  find  in  this  book  new  material 
which  is  essential  in  their  work.  Tools,  bells,  batteries,  unusual  circuits,  burglar 
alarms,  annunciators,  systems,  thermostats,  circuit  breakers,  time  alarms,  and  other 
apparatus  used  in  bell  circuits  are  described  from  the  standpoints  of  their  applica- 
tion, construction,  and  repair.  The  detailed  instructions  for  building  the  apparatus 
will  appeal  to  the  experimenter  particularly.  The  practical  worker  will  find  the 
chapters  on  Wiring  Calculation  of  Wire  Sizes  and  Magnet  Windings,  Upkeep  of 
Systems  and  the  Location  of  Faults  of  the  greatest  value  in  their  work.  124  pages. 
Fully  illustrated.  Price 60  cents 

EXPERIMENTAL  HIGH  FREQUENCY  APPARATUS  —  HOW  TO   MAKE 
AND  USE  IT.    By  THOMAS  STANLEY  CURTIS. 

This  book  tells  you  how  to  build  simple  high  frequency  coils  for  experimental  purpose 
in  the  home,  school  laboratory,  or  on  the  small  lecture  platform.  The  book  is  really 
a  supplement  to  the  same  author's  "High  Frequency  Apparatus."  The  experimental 
side  only  is  covered  in  this  volume,  which  is  intended  for  those  who  want  to  build 


small  coils  giving  up  to  an  eighteen-inch  spark.  The  book  contains  valuable  in- 
formatipn  for  the  physics  or  the  manual  training  teacher  who  is  on  the  lookout  for 
interesting  projects  for  his  boys  to  build  or  experiment  with.  The  apparatus  is 


simple,  cheap  and  perfectly  safe,  and  with  it  some  truly  startling  experiments  may  be 
performed.  Among  the  contents  are:  Induction  Coil  Outfits  Operated  on  Battery 
Current.  Kicking  Coil  Apparatus.  One-Half  Kilowatt  Transformer  Outfit.  Parts 
and  Materials,  etc.,  etc.  69  pages.  Illustrated.  Price 50  cents 

HIGH  FREQUENCY  APPARATUS,  ITS  CONSTRUCTION  AND  PRACTICAL 
APPLICATION.     By  THOMAS  STANLEY  CURTIS. 

The  most  comprehensive  and  thorough  work  on  this  interesting  subject  ever  produced. 
The  book  is  essentially  practical  in  its  treatment  and  it  constitutes  an  accurate  record 
of  the  researches  of  its  author  over  a  period  of  several  years,  during  which  time  dozens 
of  coils  were  built  and  experimented  with.  The  work  has  been  divided  into  six  basic 
parts.  The  first  two  chapters  tell  the  uninitiated  reader  what  the  high  frequency 
current  is,  what  it  is  used  for,  and  how  it  is  produced.  The  second  section,  comprising 
four  chapters,  describes  in  detail  the  principles  of  the  transformer,  condenser,  spark 
gap,  and  oscillation  transformer,  and  covers  the  main  points  in  the  design  and  con- 
struction of  these  devices  as  applied  to  the  work  in  hand.  The  third  section  covers 
the  construction  of  small  high  frequency  outfits  designed  for  experimental  work  in  the 
home  laboratory  or  in  the  classroom.  The  fourth  section  is  devoted  to  electro- 
therapeutic  and  X-Ray  apparatus.  The  fifth  describes  apparatus  for  the  cultivation 
of  plants  and  vegetables.  The  sixth  section  is  devoted  to  a  comprehensive  discussion 
of  apparatus  of  large  size  for  use  upon  the  stage  in  spectacular  productions.  The 
closing  chapter,  giving  the  current  prices  of  the  parts  and  materials  required  for  the 
construction  of  the  apparatus  described,  is  included  with  a  view  to  expediting  the 
purchase  of  the  necessary  goods.  248  pages.  Fully  illustrated.  Price  .  $2.50 

STORAGE  BATTERIES  SIMPLIFIED.    BY  VICTOR  W.  PAGE,  M.S.A.E. 

*(  A  complete  treatise  on  storage  battery  operating  principles,  repairs  and  applications. 
The  greatly  increasing  application  of  storage  batteries  in  modern  engineering  and 
mechanical  work  has  created  a  demand  for  a  book  that  will  consider  this  subject 
completely  and  exclusively.  This  is  the  most  thorough  and  authoritative  treatise 
ever  published  on  this  subject.  It  is  written  in  easily  understandable,  non-technical 
language  so  that  any  one  may  grasp  the  basic  principles  of  storage  battery  action  as 
well  as  their  practical  industrial  applications.  All  electric  and  gasoline  automobiles 
use  storage  batteries.  Every  automobile  repairman,  dealer  or  salesman  should  have  a 
good  knowledge  of  maintenance  and  repair  of  these  important  elements  of  the  motor 
car  mechanism.  This  book  not  only  tells  how  to  charge,  care  for  and  rebuild  storage 
batteries  but  also  outlines  all  the  industrial  uses.  Learn  how  they  run  street  cars, 
locomotives  and  factory  trucks.  Get  an  understanding  of  the  important  functions  they 
perform  in  submarine  boats,  isolated  lighting  plants,  railway  switch  and  signal  systems, 
marine  applications,  etc.  This  book  tells  how  they  are  used  in  central  station  standby 
service,  for  starting  automobile  motors  and  in  ignition  systems.  Every  practical  use 
of  the  modern  storage  battery  is  outlined  in  this  treatise. 

18 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


Chapters  contained  are:  Chapter  1 — Storage  Battery  Development — Types  of  Storage 
Batteries — Lead  Plate  Types — The  Edison  Cell.  Chapter  2 — Storage  Battery 
Construction — Plates  and  Grids — Plante  Plates — Faure  Plates — Non-Lead  Plates — 
Commercial  Battery  Designs.  Chapter  3— Charging  Methods — Rectifiers — Con- 
verters— Rheostats — Rules  for  Charging.  Chapter  4 — Battery  Repairs  and  Main- 
tenance. Chapter  5 — Industrial  Application  of  Storage  Batteries — Glossary  of 
Storage  Battery  Terms.  320  pages.  Fully  illustrated.  Price  ....  $2.00 

FACTORY  MANAGEMENT,  ETC. 

MODERN     MACHINE     SHOP     CONSTRUCTION,     EQUIPMENT     AND 
MANAGEMENT.    By  O.  E.  PERRIGO,  M.E. 

The  only  work  published  that  describes  the  modern  machine  shop  or  manufacturing 
plant  from  the  time  the  grass  is  growing  on  the  site  intended  for  it  until  the  finished 
product  is  shipped.  By  a  careful  study  of  its  thirty-two  chapters  the  practical  man 
may  economically  build,  efficiently  equip,  and  successfully  manage  the  modern  machine 
shop  or  manufacturing  establishment.  Just  the  book  needed  by  those  contemplating 
the  erection  of  modern  shop  buildings,  the  rebuilding  and  reorganization  of  old  ones, 
or  the  introduction  of  modern  shop  methods,  time  and  cost  systems.  It  is  a  book 
written  and  illustrated  by  a  practical  shop  man  for  practical  shop  men  who  are  too 
busy  to  read  theories  and  want  facts.  It  is  the  most  complete  all-around  book  of  its 
kind  ever  published.  It  is  a  practical  book  for  practical  men,  from  the  apprentice  in 
the  shop  to  the  president  in  the  office.  It  minutely  describes  and  illustrates  the  most 
simple  and  yet  the  most  efficient  time  and  cost  system  yet  devised.  Price  .  $5.00 

FUEL 

COMBUSTION  OF  COAL  AND  THE  PREVENTION  OF  SMOKE.    By  WM. 

M.  BARR. 

This  book  has  been  prepared  with  special  reference  to  the  generation  of  heat  by  the 
combustion  of  the  common  fuels  found  in  the  United  States,  and  deals  particularly 
with  the  conditions  necessary  to  the  economic  and  smokeless  combustion  of  bituminous 
coals  in  Stationary  and  Locomotive  Steam  Boilers. 

The  presentation  of  this  important  subject  is  systematic  and  progressive.  The  ar- 
rangement of  the  book  is  in  a  series  of  practical  questions  to  which  are  appended 
accurate  .answers,  which  describe  in  language,  free  from  technicalities,  the  several 
processes  involved  in  the  furnace  combustion  of  American  fuels;  it  clearly  states  the 
essential  requisites  for  perfect  combustion,  and  points  out  the  best  methods  for  furnace 
construction  for  obtaining  the  greatest  quantity  of  heat  from  any  given  quality  of 
coal.  Nearly  350  pages,  fully  illustrated.  Price $1.25 

SMOKE  PREVENTION  AND  FUEL  ECONOMY.     By  BOOTH  and  KERSHAW. 

As  the  title  indicates,  this  book  of  197  pages  and  75  illustrations  deals  with  the  prob- 
lem of  complete  combustion,  which  it  treats  from  the  chemical  and  mechanical 
standpoints,  besides  pointing  out  the  economical  and  humanitarian  aspects  of  the 
question.  Price $3.00 

GAS  ENGINES  AND  GAS 

THE  GASOLINE   ENGINE   ON  THE  FARM:  ITS  OPERATION,  REPAIR 
AND  USES.    By  XENO  W.  PUTNAM. 

This  is  a  practical  treatise  on  the  Gasoline  and  Kerosene  Engine  intended  for  the  man 
who  wants  to  know  just  how  to  manage  his  engine  and  how  to  apply  it  to  all  kinds  of 
farm  work  to  the  best  advantage. 

This  book  abounds  with  hints  and  helps  for  the  farm  and  suggestions  for  the  home 
and  housewife.  There  is  so  much  of  value  in  this  book  that  it  is  impossible  to  ade- 
quately describe  it  in  such  small  space.  Suffice  to  say  that  it  is  the  kind  of  a  book 
every  farmer  will  appreciate  and  every  farm  home  ought  to  have.  Includes  selecting 
the  most  suitable  engine  for  farm  work,  its  most  convenient  and  efficient  installation, 
with  chapters  on  troubles,  their  remedies,  and  how  to  avoid  them.  The  care  and 
management  of  the  farm  tractor  in  plowing,  harrowing,  harvesting  and  road  grading 
are  fully  covered ;  also  plain  directions  are  given  for  handling  the  tractor  on  the  road. 
Special  attention  is  given  to  relieving  farm  life  of  its  drudgery  by  applying  power  to 

19 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS  _ 

the  disagreeable  small  tasks  which  must  otherwise  be  done  by  hand.  Many  home- 
made contrivances  for  cutting  wood,  supplying  kitchen,  garden,  and  barn  with  water, 
loading,  hauling  and  unloading  hay,  delivering  grain  to  the  bins  or  the  feed  trough 
are  included;  also  full  directions  for  making  the  engine  milk  the  cows,  churn,  wash, 


are  ncue;  also  u  rectons  or  mang  te  engine  milk  the  cows,  churn,  wash, 
sweep  the  house  and  clean  the  windows,  etc.  Very  fully  illustrated  with  drawings  of 
working  parts  and  cuts  showing  Stationary,  Portable  and  Tractor  Engines  doing  all 
kinds  of  farm  w6rk.  All  money-making  farms  utilize  power.  Learn  how  to  utilize 
power  by  reading  the  pages  of  this  book.  It  is  an  aid  to  the  result  getter,  invaluable 
to  the  up-to-date  fanner,  student,  blacksmith,  implement  dealer  pjid,  in  fact,  all  who 
can  apply  practical  knowledge  of  stationary  gasoline  engines  or  gas  tractors  to  advan- 
tage. 530  pages.  Nearly  180  engravings.  Price.  .  ........  $2.50 


-making  farms  utilize  powe 

power  by  reading  the  pages  of  this  book.  It  is  an  aid  to  the  result  getter,  invaluable 
to  the  up-to-date  farmer,  student,  blacksmith,  implement  dealer  rjid,  in  fact,  all  who 
can  apply  practical  knowledge  of  stationary  gasoline  engines  or  gas  tractors  to  advan- 
tage. 530  pages.  Nearly  180  engravings.  Price. $2.50 

WHAT   IS    SAID    OF   THIS    BOOK: 

"Am  much  pleased  with  the  book  and  find  it  to  be  very  complete  and  up-to-date. 
I  will  heartily  recommend  it  to  students^and  farmers  whom  I  think  would  stand  in 
need  of  such  a  work,  as  I  think  it  is  an  exceptionally  good  one." — N.  S.  Gardiner 
Prof,  in  Charge,  Clemson  Agr.  College  of  S.  C.;  Dept.  of  Agri.  and  Agri.  Exp.  Station. 
Clemson  College.  S.  C. 

"I  feel  that  Mr.  Putnam's  book  covers  the  main  points  which  a  farmer  should  know." 
— R.  T.  Burdick,  Instructor  in  Agronomy,  University  of  Vermont,  Burlington,  Vt. 
"It  will  be  a  valuable  addition  to  our  library  upon  Farm  Machinery." — James  A. 
Farra,  Inst.  hi  Agri.  Engineering,  State  University  of  Ky.,  Lexington,  Ky. 

GASOLINE  ENGINES :  THEIR  OPERATION,  USE  AND  CARE.  By  A.  HYATT 
VERRILL. 

The  simplest,  latest  and  most  comprehensive  popular  work  published  on  Gasoline 
Engines,  describing  what  the  Gasoline  Engine  is ;  its  construction  and  operation ;  how 
to  install  it;  how  to  select  it;  how  to  use  it  and  how  to  remedy  troubles  encountered. 
Intended  for  Owners,  Operators  and  Users  of  Gasoh'ne  Motors  of  all  kinds.  This 
work  fully  describes  and  illustrates  the  various  types  of  Gasoline  Engines  used  in 
Motor  Boats,  Motor  Vehicles  and  Stationary  Work.  The  parts,  accessories  and 
appliances  are  described,  with  chapters  on  ignition,  fuel,  lubrication,  operation  and 
engine  troubles.  Special  attention  is  given  to  the  care,  operation  and  repair  of  motors, 
with  useful  hints  and  suggestions  on  emergency  repairs  and  makeshifts.  A  complete 
glossary  of  technical  terms  and  an  alphabetically  arranged  table  of  troubles  and  their 
symptoms  ferm  most  valuable  and  unique  features  of  this  manual.  Nearly  every 
illustration  in  the  book  is  original,  having  been  made  by  the  author.  Every  page  is 
full  of  interest  and  value.  A  book  which  you  cannot  afford  to  be  without.  275  pages. 
152  specially  made  engravings.  Price $2.00 

GAS,  GASOLINE,i AND  OIL  ENGINES.^  By  GARDNER  D.  Hiscox. 

Just  issued,  22d  revised  and  enlarged  edition.  Every  user  of  a  gas  engine  needs  this 
book.  Simple,  instructive,  and  right  up-to-date.  The  only  complete  work  on  the 
subject.  Tells  all  about  the  running  and  management  of  gas,  gasoline  and  oil  engines, 
as  designed  and  manufactured  in  the  United  States.  Explosive  motors  for  stationary 
marine  and  vehicle  power  are  fully  treated,  together  with  illustrations  of  their  parts 
and  tabulated  sizes,  also  their  care  and  running  are  included.  Electric  ignition  by 
induction  coil  and  jump  spark  are  fully  explained  and  illustrated,  including  valuable 
information  on  the  testing  for  economy  and  power  and  the  erection  of  power  plants. 
The  rules  and  regulations  of  the  Board  of  Fire  Underwriters  in  regard  to  the  installation 
and  management  of  gasoline  motors  are  given  in  full,  suggesting  the  safe  installation 
of  explosive  motor  power.  A  list  of  United  States  Patents  issued  on  gas,  gasoline,  and 
oil  engines  and  their  adjuncts  from  1875  to  date  is  included.  640  pages.  435  engrav- 
ings. Folding  plates.  Price $3.00 

GAS  ENGINE  CONSTRUCTION,  OR  HOW  TO  BUILD  A  HALF-HORSE- 
POWER GAS  ENGINE.  By  PARSELL  and  WEED. 

A  practical  treatise  of  300  pages  describing  the  theory  and  principles  of  the  action  of 
Gas  Engines  of  various  types  and  the  design  and  construction  of  a  half-horse-power 
Gas  Engine,  with  illustrations  of  the  work  in  actual  progress,  together  with  the  dimen- 
sioned working  drawings,  givmg  clearly  the  sizes  of  the  various  details:  for  the  student. 
the  scientific  investigator,  and  the  amateur  mechanic.  This  book  treats  of  the  subject 
more  from  the  standpoint  of  practice  than  that  of  theory.  The  principles  of  operation 
of  Gas  Engines  are  clearly  and  simply  described,  and  then  the  actual  construction  of  a 
half-horse-power  engine  is  taken  up,  step  by  step,  showing  in  detail  the  making  of  the 
Gas  Engine.  3d  Edition.  300  pages.  Price $3.00 

HOW  TO  RUN  AND  INSTALL  GASOLINE  ENGINES.  By  C.  VON  CULIN. 
Revised  and  enlarged  edition 'just  issued.  The  object  of  this  little  book  is  to  furnish 
a  pocket  instructor  for  the  beginner,  the  busy  man  who  uses  an  engine  for  pleasure  or 
profit,  but  who  does  not  have  the  tune  or  inclination  for  a  technical  book,  but  simply 

20 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


to  thoroughly  understand  how  to  properly  operate,  install  and  care  for  his  own  engine. 
The  index  refers  to  each  trouble,  remedy,  and  subject  alphabetically.  Being  a  quick 
reference  to  find  the  cause,  remedy  and  prevention  for  troubles,  and  to  become  an 
expert  with  his  own  engine.  Pocket  size.  Paper  binding.  Price  .  .  25  cents 

MODERN    GAS   ENGINES   AND   PRODUCER  GAS   PLANTS.     By  R.  E. 

MATHOT. 

A  guide  for  the  gas  engine  designer,  user,  and  engineer  in  the  construction,  selection, 
purchase,  installation,  operation,  and  maintenance  of  gas  engines.  More  than  one 
book  on  gas  engines  has  been  written,  but  not  one  has  thus  far  even  encroached  on  the 
field  covered  by  this  book.  Above  all  Mr.  Mathot's  work  is  a  practical  guide.  Recog- 
nizing the  need  of  a  volume  that  would  assist  the  gas  engine  user  in  understanding 
thoroughly  the  motor  upon  which  he  depends  for  power,  the  author  has  discussed  his 
subject  without  the  help  of  any  mathematics  and  without  elaborate  theoretical  ex- 
planations. Every  part  of  the  gas  engine  is  described  in  detail,  tersely,  clearly,  with 
a  thorough  understanding  of  the  requirements  of  the  mechanic.  Helpful  suggestions 
as  to  the  purchase  of  an  engine,  its  installation,  care,  and  operation,  form  a  most 
valuable  feature  of  the  work.  320  pages.  175  detailed  illustrations.  Price  .  $3.00 

THE  MODERN  GAS  TRACTOR.    By  VICTOR  W.  PAGE. 

A  complete  treatise  describing  all  types  and  sizes  of  gasoline,  kerosene  and  oil  tractors. 
Considers  design  and  construction  exhaustively,  gives  complete  instructions  for  care, 
operation  and  repair,  outlines  all  practical  applications  on  the  road  and  in  the  field. 
The  best  and  latest  work  on  farm  tractors  and  tractor  power  plants.  A  work  needed 
by  farmers,  students,  blacksmiths,  mechanics,  salesmen,  implement  dealers,  designers 
and  engineers.  500  pages.  Nearly  300  illustrations  and  folding  plates.  Price  $2.50 

CHEMISTRY  OF  GAS  MANUFACTURE.     By  H.  M.  ROYLES. 

This  book  covers  points  likely  to  arise  in  the  ordinary  course  of  the  duties  of  the 
engineer  or  manager  of  a  gas  works  not  large  enough  to  necessitate  the  employment 
of  a  separate  chemical  staff.  It  treats  of  the  testing  of  the  raw  materials  employed 
in  the  manufacture  of  illuminating  coal  gas  and  of  the  gas  produced.  The  preparation 
of  standard  solutions  is  given  as  well  as  the  chemical  and  physical  examination  of  gas 
coal.  5%  x  8%.  Cloth,  328  pages.  82  illustrations,  1  colored  plate.  Price  $5.00 

GEARING  AND  CAMS 

BEVEL  GEAR  TABLES.    By  D.  Ao.  ENGSTROM. 

A  book  that  will  at  once  commend  itself  to  mechanics  and  draftsmen.  Does  away 
with  all  the  trigonometry  and  fancy  figuring  on  bevel  gears,  and  makes  it  easy  for  any- 
one to  lay  them  out  or  make  them  just  right.  There  are  36  full-page  tables  that 
show  every  necessary  dimension  for  all  sizes  or  combinations  you're  apt  to  need.  No 
puzzling,  figuring  or  guessing.  Gives  placing  distance,  all  the  angles  (including 
cutting  angles),  and  the  correct  cutter  to  use.  A  copy  of  this  prepares  you  for  any- 
thing in  the  bevel-gear  line.  3d  Edition.  66  pages $1.25 

CHANGE  GEAR  DEVICES.    By  OSCAR  E.  PERRIGO. 

A  practical  .book  for  every  designer,  draftsman,  and  mechanic  interested  in  the  inven- 
tion and  development  of  the  devices  for  feed  changes  on  the  different  machines  requir- 
ing such  mechanism.  All  the  necessary  information  on  this  subject  is  taken  up, 
analyzed,  classified,  sifted,  and  concentrated  for  the  use  of  busy  men  who  have  not  the 
time  to  go  through  the  masses  of  irrelevant  matter  with  which  such  a  subject  is  usu- 
ally encumbered  and  select  such  information  as  will  be  useful  to  them. 
It  shows  just  what  has  been  d9ne,  how  it  has  been  done,  when  it  was  done,  and  who 
did  it.  It  saves  time  in  hunting  up  patent  records  and  re-inventing  old  ideas.  88 
pages $1.25 

DRAFTING  OF  CAMS.    By  Louis  ROUILLION. 

The  laying  out  of  cams  is  a  serious  problem  unless  you  know  how  to  go  at  it  right. 
This  puts  you  on  the  right  road  for  practically  any  kind  of  cam  you  are  likely  to  run 
up  against.  3d  Edition 35  cents 

HYDRAULICS 

HYDRAULIC  ENGINEERING.    By  GARDNER  D.  Hiscox. 

A  treatise  on  the  properties,  power,  and  resources  of  water  for  all  purposes.  Including 
the  measurement  of  streams,  the  flow  of  water  in  pipes  or  conduits ;  the  horse-power 
of  falling  water,  turbine  and  impact  water-wheels,  wave  motors,  centrifugal,  recipro- 

21 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

eating!  and  air-lift  pumps.  With  300  figures  and  diagrams  and  30  practical  tables. 
All  who  are  interested  in  water-works  development  will  find  this  book  a  useful  one, 
because  it  is  an  entirely  practical  treatise  upon  a  subject  of  present  importance,  and 
cannot  fail  in  having  a  far-reachiag  influence,  and  for  this  reason  should  nave  a  place 
in  the  working  library  of  every  engineer.  Among  the  subjects  treated  are:  Historical 
Hydraulics,  Properties  of  Water,  Measurement  of  the  Flow  of  Streams;  Flow 
from  Sub-surface  Orilices  and  Nozzles;  Flow  of  Water  in  Pipes:  Siphons  of  Various 
Kinds:  Dams  and  Great  Storage  Reservoirs:  City  and  Town  Water  Supply;  Wells 
and  Their  Reinforcement;  Air  Lift  Methods  of  Raising  Water;  Artesian  Wells; 
Irrigation  of  Arid  Districts;  Water  Power;  Water  Wheels;  Pumps  and  Pumping. 
Machinery;  Reciprocating  Pumps;  Hydraulic  Power  Transmission;  Hydraulic 
Mining;  Canals;  Ditches;  Conduits  and  Pipe  Lines;  Marine  Hydraulics;  Tidal  and 
Sea  Wave  Power,  etc.  320  pages.  Price 94.5 O 

ICE  AND  REFRIGERATION 

POCKETBOOK    OF    REFRIGERATION    AND    ICE    MAKING.    By    A.    J. 

WALLIS-TAYLOR. 

This  is  one  of  the  latest  and  most  comprehensive  reference  books  published  on  the 
subject  of  refrigeration  and  cola  storage.  It  explains  the  properties  and  refrigerating 
effect  of  the  different  fluids  in  use,  the  management  of  refrigerating  machinery  and  the 
construction  and  insulation  of  cold  rooms  with  their  required  pipe  surface  for  different 
degrees  of  cold:  freezing  mixtures  and  non-freezing  brines,  temperatures  of  cold  rooms 
for  all  kinds  of  provisions,  cold  storage  charges  for  all  classes  of  goods,  ice  making 
and  storage  of  ice,  data'and  memoranda  for  constant  reference  by  refrigerating  engineers, 
with  nearly  one  hundred  tables  containing  valuable  references  to  every  fact  and  con- 
dition required  in  the  installment  and  operation  of  a  refrigerating  plant.  New 
edition  just  published.  Price $2.00 

INVENTIONS— PATENTS 

INVENTORS'  MANUAL,  HOW  TO  MAKE  A  PATENT  PAY. 

This  is  a  book  designed  as  a  guide  to  inventors  in  perfecting  their  inventions,  taking 
out  their  patents  and  disposing  of  them.  It  is  not  infany  sense  a  Patent  Solicitor's 
Circular  nor  a  Patent  Broker's  Advertisement.  No  advertisements  of  any  description 
appear  in  the  work.  It  is  a  book  containing  a  quarter  of  a  century's  experience  of  a 
successful  inventor,  together  with  notes  based  upon  the  experience  of  many  other 
inventors. 

Among  the  subjects  treated  in  this  work  are:  How  to  Invent.  How  to  Secure  a 
Good  Patent.  Value  of  Good  Invention.  How  to  Exhibit  an  Invention.  How  to 
Interest  Capital.  How  to  Estimate  the  Value  of  a  Patent.  Value  of  Design  Patents. 
Value  of  Foreign  Patents.  Value  of  Small  Inventions.  Advice  on  Selling  Patents. 
Advice  on  the  Formation  of  Stock  Companies.  Advice  on  the  Formation  of  Limited 
Liability  Companies.  Advice  on  Disposing  of  Old  Patents.  Advice  as  to  Patent 
Attorneys.  Advice  as  to  Selling  Agents.  Forms  of  Assignments.  License  and  Con- 
tracts. State  Laws  Concerning  Patent  Rights.  1900  Census  of  the  United  States  by 
Counts  of  Over  10,000  Population.  New  revised  and  enlarged  edition.  144  pages. 
Illustrated.  Price 91.25 

KNOTS 

KNOTS,  SPLICES  AND  ROPE  WORK.    By  A.  HYATT  VERRILL. 

This  is  a  practical  book  giving  complete  and  simple  directions  for  making  all  the  most 
useful  and  ornamental  knots  hi  common  use,  with  chapters  on  Splicing,  Pointing. 
Seizing,  Serving,  etc.  This  book  is  fully  illustrated  with  one  hundred  and  fifty 
original  engravings,  which  show  how  each  knot,  tie  or  splice  is  formed,  and  its  appear- 
ance when  finished.  The  book  will  be  found  of  the  greatest  value  to  Campers,  Yachts- 
men, Travelers,  Boy  Scouts,  in  fact,  to  anyone  having  occasion  to  use  or  handle  rope 
or  knots  for  any  purpose.  The  book  is  thoroughly  reliable  and  practical,  and  is  not 
only  a  guide,  but  a  teacher.  It  is  the  standard  work  on  the  subject.  Among  the 
contents  are:  1.  Cordage,  Kinds  of  Rope.  Construction  of  Rope,  Parts  of  Rope 
Cable  and  Bolt  Rope.  Strength  of  Rope,  Weight  of  Rope.  2.  Simple  Knots  and 

and  Hitches.     4. 

.  and  Salvages.     6. 

Lashings,  Seizings  and  Splices.  7.  Fancy  Knots  and  Rope  Work.  128  pages.  150 
original  engravings.  Price 91.00 


CATALOGUE  OF   GOOD,  PRACTICAL  BOOKS 


LATHE  WORK 

LATHE  DESIGN,  CONSTRUCTION,  AND  OPERATION,  WITH  PRACTICAL 
EXAMPLES  OF  LATHE  WORK.  By  OSCAR  E.  PEBRIGO. 
A  new  revised  edition,  and  the  only  complete  American  work  on  the  subject,  written 
by  a  man  who  knows  not  only  how  work  ought  to  be  done,  but  who  also  knows  how 
to  do  it,  and  how  to  convey  this  knowledge  to  others.  It  is  strictly  up-to-date  in  its 
descriptions  and  illustrations.  Lathe  history  and  the  relations  of  the  lathe  to  manu- 
facturing are  given;  also  a  description  of  the  various  devices  for  feeds  and  thread 
cutting  mechanisms  from  early  efforts  in  this  direction  to  the  present  time.  Lathe 
design  is  thoroughly  discussed,  including  back  gearing,  driving  cones,  thread-cutting 
gears,  and  all  the  essential  elements  of  the  modern  lathe.  The  classification  of  lathes 


is  taken  up,  giving  the  essential  differences  of  the  several  types  of  lathes  including, 
as  is  usually  understood,  engine  lathes,  bench  lathes,  speed  lathes,  forge  lathes,  gap 
lathes,  pulley  lathes,  forming  lathes,  multip.e-spindle  lathes,  rapid-reduction  lathes. 


precision  lathes,  turret  lathes,  special  lathes,  electrically-driven  lathes,  etc.  In  addi- 
tion to  the  complete  exposition  on  construction  and  design,  much  practical  matter  on 
lathe  installation,  care  and  operation  has  been  incorporated  in  the  enlarged  1915  edi- 
tion. All  kinds  of  lathe  attachments  for  drilling,  milling,  etc.,  are  described  and 
complete  instructions  are  given  to  enable  the  novice  machinist  to  grasp  the  art  of  lathe 
operation  as  well  as  the  principles  involved  in  design.  A  number  of  difficult  machining 
operations  are  described  at  length  and  illustrated.  The  new  edition  has  nearly  500 
pages  and  350  illustrations.  Price  .  .  ..........  $3.00 

WHAT   IS   SAID    OF   THIS    BOOK: 

"  This  is  a  lathe  book  from  beginning  to  end,  and  is  just  the  kind  of  a  book  which  one 
delights  to  consult,  —  a  masterly  treatment  of  the  subject  in  hand."  —  Engineering  Neics. 
"  This  work  will  be  of  exceptional  interest  to  anyone  who  is  interested  in  lathe  practice, 
as  one  very  seldom  sees  such  a  complete  treatise  on  a  subject  as  this  is  on  the  lathe."  — 
Canadian  Machinery.  . 

TURNING  AND  BORING  TAPERS.    By  FRED  H.  COLVTN. 

There  are  two  ways  to  turn  tapers;  the  right  way  and  one  other.  This  treatise  has 
to  do  with  the  right  way;  it  tells  you  how  to  start  the  work  properly,  how  to  set  the 
lathe,  what  tools  to  use  and  how  to  use  them,  and  forty  and  one  other  little  things 
that  you  should  know.  Fourth  edition.  Price  .........  35  cents 

LIQUID  AIR 

LIQUID  AIR  AND  THE  LIQUEFACTION  OF  GASES.    By  T.  O'CoxoR  SLOANE. 

This  book  gives  the  history  of  'the  theory,  discovery,  and  manufacture  of  Liquid  Air, 

and  contains  an  illustrated  description  of  all  the  experiments  that  have  excited  the 

wonder  of  audiences  all  over  the  country.     It  shows  how  liquid  air,  like  water,  is 

carried  hundreds  of  miles  and  is  handled  in  open  buckets.     It  tells  what  may  be  ex- 

pected from  it  in  the  near  future. 

A  book  that  renders  simple  one  of  the  most  perplexing  chemical  problems  of  the 

century.     Startling  developments  illustrated  by  actual  experiments. 

It  is  not  only  a  work  of  scientific  interest  and  authority,  but  is  intended  for  the  general 

reader,  being  written  in  a  popular  style  —  easily  understood  by  every  one.     Second 

edition.     365  pages.    Price    .................     $2.50 

LOCOMOTIVE  ENGINEERING 

AIR-BRAKE  CATECHISM.    By  ROBERT  H.  BLACKALL. 

This  book  is  a  standard  text  book.  It  covers  the  "Westinshouse  Air-Brake  Equipment, 
including  the  No.  5  and  the  No.  6  E.  T.  Locomotive  Brake  Equipment;  the  K  (Quick 
Service)  Triple  Valve  for  Freight  Service;  and  the  Cross-Compound  Pump.  The 
operation  of  all  parts  of  the  apparatus  is  explained  in  detail,  and  a  practical  way  of 
finding  their  peculiarities  and  defects,  with  a  proper  remedy,  is  given.  It  contains 
2,000  questions  with  their  answers,  which  will  enable  any  railroad  man  to  pass  any 
examination  on  the  subject  of  Air  Brakes.  Endorsed  and  used  by  air-brake  instruc- 
tors and  examiners  on  nearly  every  railroad  in  the  United  States.  27th  Edition.  411 
pages,  fully  illustrated  with  colored  plates  and  diagrams.  Price  .....  $3.50 

23 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 

AMERICAN  COMPOUND  LOCOMOTIVES.    By  FBED  H.  COLVIN. 

The  only  book  on  compounds  for  the  engineman  or  shopman  that  shows  in  a  plain, 
practical  way  the  various  features  of  compound  locomotives  in  use.  Shows  how  they 
are  made,  what  to  do  when  they  break  down  or  balk.  Contains  sections  as  follows: — 
•A  Bit  of  History.  Theory  of  Compounding  Steam  Cylinders.  Baldwin  Two-Cylinder 
Compound.  Pittsburg  Two-Cylinder  Compound.  Rhode  Island  Compound.  Rich- 
mond Compound.  Rogers  Compound.  Schenectady  Two-Cylinder  Compound. 
Vauclain  Compound.  Tandem  Compounds.  Baldwin  Tandem.  The  Colvin-Wight- 
man  Tandem.  Schenectady  Tandem.  Balanced  Locomotives.  Baldwin  Balanced 
Compound.  Plans  for  Balancing.  Locating  Blows.  Breakdowns.  Reducing  Valves. 
Drifting.  Valve  Motion.  Disconnecting.  Power  of  Compound  Locomotives.  Practi- 
cal Notes. 

Fully  illustrated  and  containing  ten  special  "  Duotone"  inserts  on  heavy  Plate  Paper, 
showing  different  types  of  Compounds.  142  pages.  Price $1.00 

COMBUSTION  OF  COAL  AND  THE  PREVENTION  OF  SMOKE.    By  WM. 
M.  BARR. 

This  book  has  been  prepared  with  special  reference  to  the  generation  of  heat  by  the 
combustion  of  the  common  fuels  found  in  the  United  States  and  deals  particularly 
with  the  conditions  necessary  to  the  economic  and  smokeless  combustion  of  bituminous 
coal  in  Stationary  and  Locomotive  Steam  Boilers. 

Presentation  of  this  important  subject  is  systematic  and  progressive.  The  ar- 
rangement of  the  book  is  in  a  series  of  practical  questions  to  which  are  appended 
accurate  answers,  which  describe  in  language  free  from  technicalities  the  several 
processes  involved  in  the  furnace  combustion  of  American  fuels;  it  clearly  states  the 
essential  requisites  for  perfect  combustion,  and  points  out  the  best  methods  of  furnace 
construction  for  obtaining  the  greatest  quantity  of  heat  from  any  given  quality  of 
coal.  Nearly  350  pages,  fully  illustrated.  Price $  1 .25 

DIARY  OF  A  ROUND-HOUSE  FOREMAN.    By  T.  S.  REILLT. 

This  is  the  greatest  book  of  railroad  experienced  ever  published.  Containing  a  fund  of 
information  and  suggestions  along  the  line  of  handling  men,  organizing,  etc..  that  one 
cannot  afford  to  miss.  176  pages.  Price _.  $1.25 


LINK  MOTIONS,  VALVES  AND  VALVE  SETTING.  By  FRED  H.  COLVIN, 
Associate  Editor  of  American  Machinist. 

A  handy  book  for  the  engineer  or  machinist  that  clears  up  the  mysteries  of  valve 
setting.  Shows  the  different  valve  gears  in  use.  how  they  work,  and  why.  Piston 
and  slide  valves  of  different  types  are  illustrated  and  explained.  A  book  that  every 
railroad  man  in  the  motive  power  department  ought  to  have.  Contains  chapters  on 
Locomotive  Link  Motion,  Valve  Movements,  Setting  Slide  Valves,  Analysis  by 
Diagrams,  Modern  Practice,  Slip  of  Block,  Slice  Valves,  Piston  Valves,  Setting  Piston 
Valves,  Joy-Allen  Valve  Gear,  Walschaert  Valve  Gear,  Gooch  Valve  Gear,  Alfree- 
Hubbell  Valve  Gear,  etc.,  etc.  Fully  illustrated.  Price SO.cents 

LOCOMOTIVE  BOILER  CONSTRUCTION.    By  FRANK  A.  KLEINHANS. 

The  construction  of  boilers  in  general  is  treated,  and,  following  this,  the  locomotive 
boiler  is  taken  up  hi  the  order  in  which  its  various  parts  go  through  the  shop.  Shows 
all  types  of  boilers  used ;  gives  details  of  construction ;  practical  facts,  such  as  life  of 
riveting,  punches  and  dies;  work  done  per  day,  allowance  for  bending  and  flanging 
sheets,  and  other  data.  Including  the  recent  Locomotive  Boiler  Inspection  Laws 
and  Examination  Questions  with  their  answers  for  Government  Inspectors.  Contains 
chapters  on  Laying  Out  Work;  Flanging  and  Forging;  Punching;  Shearing;  Plate 
Planing;  General  Tables;  Finishing  Parts;  Bending;  Machinery  Parts;  Riveting; 
Boiler  Details;  Smoke  Box  Details;  Assembling  and  Calking;  Boiler  Shop 
Machinery,  etc.,  etc. 

There  isn't  a  man  who  has  anything  to  do  with  boiler  work,  either  new  or  repair  work, 
who  doesn't  need  this  book.  The  manufacturer,  superintendent,  foreman,  and  boiler 
worker — all  need  it.  No  matter  what  the  tyne  of  boiler,  you'll  find  a  mint  of  informa- 
tion that  you  wouldn't  be  without.  Over  400  pages,  five  large  folding  plates. 
Price $3.50 

LOCOMOTIVE  BREAKDOWNS  AND  THEIR  REMEDIES.  By  GEO.  L. 
FOWLER.  Revised  by  WM.  W.  WOOD,  Air-Brake  Instructor.  Just  issued. 
Revised  pocket  edition. 

It  is  out  of  the  question  to  try  and  tell  you  about  every  subject  that  is  covered  in  this 
pocket  edition  of  Locomotive  Breakdowns.  Just  imagine  all  the  common  troubles 
that  an  engineer  may  expect  to  happen  some  time,  and  then  add  all  of  the  unexpected 

24 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 

ones,  troubles  that  could  occur,  but  that  you  have  never  thought  about,  and  you  will 
find  that  they  are  all  treated  with  the  very  best  methods  of  repair.  Walschaert 
Locomotive  Valve  Gear  Troubles,  Electric  Headlight  Troubles,  as  well  as  Questions 
and  Answers  on  the  Air  Brake  are  all  included.  312  pages.  8th  Bevised  Edition. 
Fully  illustrated $1.25 

LOCOMOTIVE  CATECHISM.    By  ROBERT  GBIMSHAW. 

The  revised  edition  of  "Locomotive  Catechism,"  by  Robert  Grimshaw,  is  a  New  Book 
from  Cover  to  Cover.  It  contains  twice  as  many  pages  and  double  the  number  of 
illustrations  of  previous  editions.  Includes  the  greatest  amount  of  practical  informa- 
tion ever  pubh'shed  on  the  construction  and  management  of  modern  locomotives. 
Specially  Prepared  Chapters  on  the  Walschaert  Locomotive  Valve  Gear,  the  Alr- 
Brake  Equipment  and  the  Electric  Headlight  are  given. 

It  commends  itself  at  once  to  every  Engineer  and  Fireman,  and  to-all  who  are  going  in 
for  examination  or  promotion.  In  plain  language,  with  full,  complete  answers,  not  only 
all  the  questions  asked  by  the  examining  engineer  are  given,  but  those  which  the 
young  and  loss  experienced  would  ask  the  veteran,  and  which  old  hands 


is  ask  as  "stick- 
ers."    It  is  a  veritable  Encyclopedia  of  the  Locomotive,  is  entirely  free  from  mathe- 


matics, easily  imderstood  and  thoroughly  up-to-date.  Contains  over  4,000  Examina- 
tion Questions  with  their  Answers.  825  pages,  437  illustrations  and  three  folding 
plates.  2Sth  Revised  Edition.  Price $2.50 


and  the  Two-Cylinder  Simple  Engine;  Compounding  and  Superheating;  Designs  of 
Locomotive    Superheaters;     Constructive    Details     of    Locomotives    Using    Hig~~ 
Superheated  Steam.     Experimental  and  Working  Results.     Illustrated  with  folc 


APPLICATION  OF  HIGHLY  SUPERHEATED  STEAM  TO  LOCOMOTIVES. 

By  ROBERT  GARBE. 

A  practical  book  which  cannot  be  recommended  too  highly  to  those  motive-power 
men  who  are  anxious  to  maintain  the  highest  efficiency  in  their  locomotives.  .  Con- 
tains special  chapters  on  Generation  of  Highly  Superheated  Steam ;  Superheated  Steam 

-  -        rheating;  Designs  of 
tives    Using    Highly 
strated  with  folding 
plates  and  tables.     Cloth.     Price $3.0O 

PRACTICAL  INSTRUCTOR  AND  REFERENCE  BOOK  FOR  LOCOMOTIVE 
FIREMEN  AND  ENGINEERS.  By  CHAS.  F.  LOCKHART. 
An  entirely  new  book  on  the  Locomotive.  It  appeals  to  every  railroad  man,  as  it 
tells  him  how  things  are  done  and  the  right  way  to  do  them.  Written  by  a  man  who 
has  had  years  of  practical  experience  in  locomotive  shops  and  on  the  road  firing  and 
running.  The  information  given  in  this  book  cannot  be  found  in  any  other  similar 
treatise.  Eight  hundred  and  fifty-one  questions  with  their  answers  are  included, 
which  will  prove  specially  helpful  to  those  preparing  for  examination.  Practical 
information  on:  The  Construction  and  Operation  of  Locomotives;  Breakdowns  and 
their  Remedies;  Air  Brakes  and  Valve  Gears.  Rules  and  Signals  are  handled  in  a 
thorough  manner.  As  a  book  of  reference  it  cannot  be  excelled.  The  book  is  divided 
into  six  parts,  as  follows:  1.  The  Fireman's  Duties.  2.  General  Description  of  the 
Locomotive.  3.  Breakdowns  and  their  Remedies.  4.  Air  Brakes.  5.  Extracts 
from  Standard  Rules.  6.  Questions  for  Examination.  The  851  questions  have  been 
carefulty  selected  and  arranged.  These  cover  the  examinations  required  by  the 
different  railroads.  368  pages.  88  illustrations.  Price $2.0O 

PREVENTION  OF  RAILROAD  ACCIDENTS,  OR  SAFETY  IN  RAILROADING. 

By  GEORGE  BRADSHAW. 

This  book  is  a  heart-to-heart  talk  with  Railroad  Employees,  dealing  with  facts,  not 
theories,  and  showing  the  men  in  the  ranks,  from  every-day  experience,  how  accidents 
occur  and  how  they  may  be  avoided.  The  book  is  illustrated  with  seventy  original 
photographs  and  drawings  showing  the  safe  and  unsafe  methods  of  work.  No  vision- 
ary schemes,  no  ideal  pictures.  Just  plain  facts  and  Practical  Suggestions  are  given. 
Every  railroad  employee  who  reads  the  book  is  a  better  and  safer  man  to  have  in 
railroad  service.  It  gives  just  the  information  which  will  be  the  means  of  preventing 
many  injuries  and  deaths.  All  railroad  employees  should  procure  a  copy;  read  it, 
and  do  your  part  in  preventing  accidents.  169  pages.  Pocket  size.  Fully  illustrated. 
Price 60  cents 

TRAIN  RULE  EXAMINATIONS  MADE  EASY.  By  G.  E.  COLLINGWOOD. 
This  is  the  only  practical  work  on  train  rules  in  print.  Every  detail  is  covered,  and 
puzzling  points  are  explained  in  simple,  comprehensive  language,  making  it  a  practical 
treatise  for  the  Train  Dispatcher,  Engineman,  Trainman,  and  all  others  who  have  to 
do  with  the  movements  of  trains.  Contains  complete  and  reliable  information  of  the 
Standard  Code  of  Train  Rules  for  single  track.  Shows  Signals  in  Colors,  as  used  on 
the  different  roads.  Explains  fully  the  practical  application  of  train  orders,  giving  a 
clear  and  definite  understanding  of  all  orders  which  may  be  used.  The  meaning  and 
necessity  for  certain  rules  are  explained  in  such  a  manner  that  the  student  may  know 
beyond  a  doubt  the  rights  conferred  under  any  orders  he  may  receive  or  the  action 

25 


CATALOGUE   OF   GOOD,  PRACTICAL  BOOKS 

required  by  certain  rules.  As  nearly  all  roads  require  trainmen  to  pass  regular  exami- 
nations, a  complete  set  of  examination  questions,  with  their  answers,  arc  included. 
These  will  enable  the  student  to  pass  the  required  examinations  with  credit  to  himself 
and  the  road  for  which  he  works.  256  pages.  Fully  illustrated  with  Train  Signals 
in  Colors.  Price $1.5O 

THE  WALSCHAERT  AND  OTHER  MODERN  RADIAL  VALVE  GEARS  FOR 
LOCOMOTIVES.     By  WM.  W.  WOOD. 

If  you  would  thoroughly  understand  the  Walschaert  Valve  Gear  you  should  possess  a 
copy  of  this  book,  as  the  author  takes  the  plainest  form  of  a  steam  engine.- — a  stationary 
engine  in  the  rough,  that  will  only  turn  its  crank  in  one  direction — and  from  it  builds 
up — with  the  reader's  help — a  modern  locomotive  equipped  with  the  Walschaert 
Valve  Gear,  complete.  The  points  discussed  are  clearly  illustrated ;  two  large  folding 
plates  that  show  the  positions  of  the  valves  of  both  inside  or  outside  admission  type,  as 
well  as  the  links  and  other  parts  of  the  gear  when  the  crank  is  at  nine  different  points 
in  its  revolution,  are  especially  valuable  in  making  the  movement  clear.  These  employ 
sliding  cardboard  models  which  are  contained  in  a  pocket  in  the  cover. 
The  book  is  divided  Into  five  general  divisions,  as  follows:  1.  Analysis  of  the  gear. 
2.  Designing  and  erecting  the  gear.  3.  Advantages  of  the  gear.  4.  Questions  and 
answers  relating  to  the  Walschaert  Valve  Gear.  5.  Setting  valves  with  the  Wal- 
schaert Valve  Gear;  the  three  primary  types  of  locomotive  valve  motion;  modem 
radial  valve  gears  other  than  the  Walschaert;  the  Hobart  All-free  Valve  and  Valve 
Gear,  with  questions  and  answers  on  breakdowns;  the  Baker-Pilliod  Valve  Gear;  the 
Improved  Baker-Pilliod  Valve  Gear,  with  questions  and  answers  on  breakdowns. 
The  questions  with  full  answers  given  will  be  especially  valuable  to  firemen  and  engi- 
neers in  preparing  for  an  examination  for  promotion.  245  pages.  Third  Revised 
Edition.  Price $2.00 

WESTINGHOUSE  E-T  AIR-BRAKE  INSTRUCTION  POCKET  BOOK.    By 

WM.  W.  WOOD,  Air-Brake  Instructor. 

Here  is  a  book  for  the  railroad  man,  and  the  man  who  aims  to  be  one.  It  is  without 
doubt  the  only  complete  work  published  on  the  Westinghouse  E-T  Locomotive  Brake 
Equipment.  Written  by  an  Air-Brake  Instructor  who  knows  just  what  is  needed.  It 
covers  the  subject  thoroughly.  Everything  about  the  New  Westinghouse  Engine  and 
Tender  Brake  Equipment,  including  the  standard  No.  5  and  the  Perfected  No.  6 
style  of  brake,  is  treated  in  detail.  Written  in  plain  English  and  profusely  illustrated 
with  Colored  Plates,  which  enable  one  to  trace  the  flow  of  pressures  throughout  the 
entire  equipment.  The  best  book  ever  published  on  the  Air  Brake.  Equally  good  for 
the  beginner  and  the  advanced  engineer.  Will  pass  any  one  through  any  examination. 
It  informs  and  enlightens  you  on  every  point.  Indispensable  to  every  engineman  and 
trainman.  . 

Contains  examination  questions  and  answers  on  the  E-T  equipment.  Covering  what 
the  E-T  Brake  is.  How  it  should  be  operated.  What  to  do  when  defective.  Not  a 
question  can  be  asked  of  the  engineman  up  for  promotion,  on  either  the  No.  5  or  the 
No.  6  E-T  equipment,  that  is  not  asked  and  answered  in  the  book.  If  you  want  to 
thoroughly  understand  the  E-T  equipment  get  a  copy  of  this  book.  It  covers  every 
detail.  Makes  Air-Brake  troubles  and  examinations  easy.  Price  .  .  .  .  $2.00 

MACHINE-SHOP  PRACTICE 

AMERICAN  TOOL  MAKING  AND  INTERCHANGEABLE  MANUFACTURE 
ING.    By  J.  V.  WOODWORTH. 

A  "shoppy"  book,  containing  no  theorizing,  no  problematical  or  experimental  devices, 
there  are  no  badly  proportioned  and  impossible  diagrams,  no  catalogue  cuts,  but  a 
valuable  collection  of  drawings  and  descriptions  of  devices,  the  rich  fruits  of  the  author's 
own  experience.  In  its  500-odd  pages  the  one  subject  only.  Tool  Making,  and  what- 
ever relates  thereto,  is  dealt  with.  The  work  stands  without  a  rival.  It  is  a  complete 
practical  treatise  on  the  art  of  American  Tool  Making  and  system  of  interchangeable 
manufacturing  as  carried  on  to-day  in  the  United  States.  In  it  are  described  and 
illustrated  all  of  the  different  types  and  classes  of  small  tools,  fixtures,  devices,  and 
special  appliances  which  are  in  general  use  in  all  machine-manufacturing  and  metal- 
working  establishments  where  economy,  capacity,  and  interchangeability  in  the  pro- 
duction of  machined  metal  parts  are  imperative.  The  science  of  jig  making  is  exhaus- 
tively discussed,  and  particular  attention  is  paid  to  drill  jigs,  boring,  profiling  and  milling 
fixtures  and  other  devices  hi  which  the  parts  to  be  machined  are  iocated  and  fastened 
within  the  contrivances.  All  of  the  tools,  fixtures,  and  devices  illustrated  and  de- 
scribed have  been  or  are  used  for  the  actual  production  of  work,  such  as  parts  of  drill 
presses,  lathes,  patented  machinery,  typewriters,  electrical  apparatus,  mechanical  ap- 
pliances, brass  goods,  composition  parts,  mould  products,  sheet  metal  articles,  drop- 
forgings,  jewelry,  watches,  medals,  coins,  etc.  531  pages.  Price  ....  $4.50 

26 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


MACHINE-SHOP  ARITHMETIC.     By  COLVIN-CHENEY. 

This  is  an  arithmetic  of  the  things  you  have  to  do  with  daily.  It  tells  you  plainly 
about:  how  to  find  areas  in  figures;  how  to  find  surface  or  volume  of  balls  or  spheres; 
handy  ways  for  calculating;  about  compound  gearing;  cutting  screw  threads  on  any 
lathe;  drilling  for  taps;  speeds  of  drills;  taps,  emery  wheels,  grindstones,  milling 
cutters,  etc.;  all  about  the  Metric  system  with  conversion  tables;  properties  of  metals; 
strength  of  bolts  and  nuts;  decimal  equivalent  of  an  inch.  All  sorts  of  machine-shop 
figuring  and  1,001  other  things,  any  one  of  which  ought  to  be  worth  more  than 
the  price  of  this  book  to  you,  and  it  saves  you  the  trouble  of  bothering  the  boss.  6th 
edition.  131  pages.  Price 60  cents 

MODERN  MACHINE-SHOP  CONSTRUCTION,  EQUIPMENT  AND  MAN- 
AGEMENT. By  OSCAR  E.  PERRIGO. 

The  only  work  published  that  describes  the  Modern  Shop  or  Manufacturing  Plant 
from  the  time  the  grass  is  growing  on  the  site  intended  for  it  until  the  finished  product 
is  shipped.  Just  the  book  needed  by  those  contemplating  the  erection  of  modern  shop 
buildings,  the  rebuilding  and  reorganization  of  old  ones,  or  the  introduction  of  Modern 
Shop  Methods,  time  and  cost  systems.  It  is  a  book  written  and  illustrated  by  a  prac- 
tical shop  man  for  practical  shop  men  who  are  too  busy  to  read  theories  and  want  facts. 
It  is  the  most  complete  all-round  book  of  its  kind  ever  published.  400  large  quarto 
pages.  225  original  and  specially-made  illustrations.  2d  Revised  and  Enlarged 
Edition.  Price $5.00 

"  SHOP  KINKS."     By  ROBERT  GRIMSHAW. 

A  book  of  400  pages  and  222  illustrations,  being  entirely  different  from  any  other 
book  on  machine-shop  practice.  Departing  from  conventional  style,  the  author 
avoids  universal  or  common  shop  usage  and  limits  his  work  to  showing  special  ways 
of  doing  things  better,  more  cheaply  and  more  rapidly  than  usual.  As  a  result  the 
advanced  methods  of  representative  establishments  of  the  world  are  placed  at  the 
disposal  of  the  reader.  This  book  shows  the  proprietor  where  large  savings  are  possible, 
and  how  products  may  be  improved.  To  the  employee  it  holds  out  suggestions  that, 
properly  applied,  will  hasten  his  advancement.  No  shop  can  afford  to  be  without  it. 
It  bristles  with  valuable  wrinkles  and  helpful  suggestions.  It  will  benefit  all,  from 
apprentice  to  proprietor.  Every  machinist,  at  any  age,  should  study  its  pages.  Fifth 
edition.  Price $3.00 

THREADS  AND  THREAD  CUTTING.    By  COLVIN  and  STABEL. 

This  clears  up  many  of  the  mysteries  of  thread-cutting,  such  as  double  and  triple 
threads,  internal  threads,  catching  threads,  use  of  hobs,  etc.  Contains  a  lot  of  useful 
hints  and  several  tables.  Third  edition.  Price 35  cents 

EVERYDAY  ENGINEERING— THE  BEST  MECHANICAL  MAGAZINE  ON 
THE  MARKET.  ONLY  ONE  DOLLAR  AND  FIFTY  CENTS  A  YEAR 
FOR  TWELVE  NUMBERS.  SUBSCRIBE  TO-DAY. 

Every  practical  man  needs  a  magazine  which  will  tell  him  how  to  make  and  do  things. 
A  monthly  magazine  devoted  to  practical  mechanics  for  every-day  men.  Its  aim  is 
to  popularize  engineering  as  a  science,  teaching  the  elements  of  applied  mechanics 
and  electricity  in  a  straightforward  and  understandable  manner.  The  magazine 
maintains  its  own  experimental  laboratory,  where  the  devices  described  in  articles 
submitted  to  the  Editor  are  first  tried  out  and  tested  before  they  are  published.  This 
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The  magazine  is  the  only  one  hi  this  country  that  specializes  in  practical  model  build- 
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The  magazine  entertains  while  it  instructs.     It  is  a  journal  of  practical,  dependable 
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Sample  copy  sent  on  receipt  of  fifteen  cents. 
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27 


CATALOGUE   OF  GOOD,   PRACTICAL  BOOKS 


THE  WHOLE  FIELD  OF  MECHANICAL  MOVEMENTS 
COVERED  BY  MR.  HISCOX'S  TWO  BOOKS 


We  publish  two  books  by  Gardner  D.  Hiscox  that  will  keep  you  from  "inventing"  things 
that  haw  been  done  before,  and  suggest  ways  of  doing  things  that  you  have  not  thought  of 
before.  Many  a  man  spends  time  and  money,  pondering  over  some  mechanical  problem, 
only  to  learn,  after  he  has  solved  the  problem,  that  the  same  thing  has  been  accomplished 
and  put  in  practice  by  others  long  before.  Time  and  money  spent  in  an  effort  to  accom- 
plish what  has  already  been  accomplished  are  time  and  money  LOST.  The  whole  field 
of  mechanics,  every  known  mechanical  movement,  and  practically  every  device  is  covered 
by  these  two  books.  If  the  thing  you  want  has  been  invented,  it  is  illustrated  in  them.  If 
it  hasn't  been  invented,  then  you'll  find  in  them  the  nearest  things  to  what  you  want,  some 
movements  or  devices  that  will  apply  in  your  case,  perhaps;  or  which  will  give  you  a  key 
from  which  to  work.  No  book  or  set  of  books  ever  published  is  of  more  real  value  to  the 
Inventor,  Draftsman,  or  practical  Mechanic  than  the  two  volumes  described  below. 

MECHANICAL  MOVEMENTS,  POWERS,  AND  DEVICES.    By  GARDNER  D. 
Hiscox. 

This  is  a  collection  of  1,890  engravings  of  different  mechanical  motions  and  appliances, 
accompanied  by  appropriate  text,  making  it  a  book  of  great  value  to  the  inventor, 
the  draftsman,  and  to  all  readers  with  mechanical  tastes.  The  book  is  divided  into 
eighteen  sections  or  chapters,  in  which  the  subject-matter  is  classified  under  the  follow- 
ing heads:  Mechanical  Powers;  Transmission  of  Power;  Measurement  of  Power; 
Steam  Power;  Air  Power  Appliances;  Electric  Power  and  Construction;  Navigation 
and  Roads;  Gearing;  Motion  and  Devices;  Controlling  Motion;  Horological; 
Mining;  Mill  and  Factory  Appliances;  Construction  and  Devices;  Drafting  Devices; 
Miscellaneous  Devices,  etc.  15th  edition  enlarged.  400  octavo  pages.  Price  .  $3.00 

MECHANICAL  APPLIANCES,  MECHANICAL  MOVEMENTS  AND  NOVEL- 
TIES OF  CONSTRUCTION.    By  GARDNER  D.  Hiscox. 

This  is  a  supplementary  volume  to  the  one  upon  mechanical  movements.  Unlike  the 
first  volume,  which  is  more  elementary  in  character,  this  volume  contains  illustrations 
and  descriptions  of  many  combinations  of  motions  and  of  mechanical  devices  and 
appliances  found  in  different  lines  of  machinery,  each  device  being  shown  by  a  line 
drawing  with  a  description  showing  its  working  parts  and  the  method  of  operation. 
From  the  multitude  of  devices  described  and  illustrated  might  be  mentioned,  in 
passing,  such  items  as  conveyors  and  elevators,  Prony  brakes,  thermometers,  various 
types  of  boilers,  solar  engines,  oil-fuel  burners,  condensers,  evaporators,  Corliss  and 
other  valve  gears,  governors,  gas  engines,  water  motors  of  various  descriptions,  air- 
ships, motors  and  dynamos,  automobile  and  motor  bicycles,  railway  lock  signals, 
car  couplers,  link  and  gear  motions,  ball  bearings,  breech  block  mechanism  for  heavy 
guns,  and  a  large  accumulation  of  others  of  equal  importance.  1,000  specially  made 
engravings.  396  octavo  pages.  4th  Edition  enlarged.  Price $3.00 

MACHINE-SHOP  TOOLS  AND  SHOP  PRACTICE.    By  W.  H.  VANDERVOORT. 

A  work  of  555  pages  and  673  illustrations,  describing  in  every  detail  the  construction, 
operation,  and  manipulation  of  both  hand  and  machine  tools.  Includes  chapters 
on  filing,  fitting,  and  scraping  surfaces;  on  drills,  reamers,  taps,  and  dies;  the  lathe 
and  its  tools;  planers,  shapers,  and  their  tools;  milling  machines  and  cutters;  gear 
cutters  and  gear  cutting;  drilling  machines  and  drill  work;  grinding  machines  and 
their  work;  hardening  and  tempering;  gearing,  belting,  and  transmission  machinery; 
.  Pri 


useful  data  and  tables.     6th  edition.     Price $4.25 

THE  MODERN  MACHINIST.    By  JOHN  T.  USHER. 

This  is  a  book  showing,  by  plain  description  and  by  profuse  engravings  made  expressly 
for  the  work,  all  that  is  best,  most  advanced,  and  of  the  highest  efficiency  in  modern 
machine-shop  practice,  tools,  and  implements,  showing  the  way  by  which  and  through 
which,  as  Mr.  Maxim  says,  "American  machinists  have  become  and  are  the  finest  me- 
chanics in  the  world."  Indicating  as  it  does,  in  every  line,  the  familiarity  of  the  author 
with  every  detail  of  daily  experience  in  the  shop,  it  cannot  fail  to  be  of  service  to  any 
man  practically  connected  with  the  shaping  or  finishing  of  metals. 
There  is  nothing  experimental  or  visionary  about  the  book,  all  devices  being  in  actual 
use  and  giving  good  results.  It  might  be  called  a  compendium  of  shop  methods, 
showing  a  variety  of  special  tools  and  appliances  which  will  give  new  ideas  to  many 
mechanics,  from  the  superintendent  down  to  the  man  at  the  bench.  It  will  be  found 

28 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 


a  valuable  edition  to  any  machinist's  library,  and  should  be  consulted  whenever  a 
new  or  difficult  job  is  to  be  done,  whether  it  is  boring,  milling,  turning,  or  planing, 
as  they  are  all  treated  in  a  practical  manner.  Fifth  edition.  320  pages.  250  Illustra- 
tions. Price $2.50 

HENLEY'S  ENCYCLOPEDIA  OF  PRACTICAL  ENGINEERING  AND  ALLIED 
TRADES.  Edited  by  JOSEPH  G.  HORNER,  A.M.I.Mech.E. 

This  book  covers  the  entire  practice  of  Civil  and  Mechanical  Engineering.  The 
best  known  experts  in  all  branches  of  engineering  have  contributed  to  these  volumes. 
The  Cyclopedia  is  admirably  well  adapted  to  the  needs  of  the  beginner  and  the  self- 
taught  practical  man,  as  well  as  the  mechanical  engineer,  designer,  draftsman,  shop 
superintendent,  foreman  and  machinist. 

It  is  a  modern  treatise  in  five  volumes.  Handsomely  hound  in  half  morocco,  each 
volume  containing  nearly  500  pages,  with  thousands  of  illustrations,  including  dia- 
grammatic and  sectional  drawings  with  full  explanatory  details.  For  the  complete 
set  of  five  volumes.  Price $30.00 

MODEL  MAKING  Including  Workshop  Practice,  Design  and  Construction  of 
Models.  Edited  by  RAYMOND  F.  YATES.  Editor  of  "  Everyday  Engineering 
Magazine." 

This  book  does  not  describe  the  construction  of  toys.  Its  pages  are  devoted  to  model 
engineering  and  the  mechanical  sciences  associated  with  it.  It  contains  descriptions 
with  illustrations  of  the  complete  models  made  by  some  of  the  leading  model  engineers 
in  this  country.  It  is  the  only  book  published  on  this  important  subject. 
The  first  part  of  the  book  is  devoted  to  the  mechanical  sciences  and  processes  related 
to  model  engineering  and  mechanics  hi  general.  To  the  inexperienced  workman,  who 
wishes  to  make  models  but  is  untrained  in  the  fundamental  mechanics,  this  book  will 
afford  all  the  information  necessary.  For  the  experienced  mechanic,  there  are  many 
hints  and  short  cuts  that  will  be  found  helpful.  Few  mechanics,  no  matter  how  well 
trained,  know  how  to  make  their  own  patterns.  Yet  a  complete  treatise  on  this  im-* 
portant  craft  is  given.  The  same  holds  true  in  regard  to  the  intelligent  use  of  abrasives 
in  the  home  shop.  This,  too,  is  completely  covered  in  a  way  that  will  not  only  help  the 
beginner  but  teach  the  trained  man  a  few  things  that  he  may  not  have  understood* 
before.  In  short,  the  fore  part  of  the.book  will  prepare  men  to  more  thoroughly  under- 
stand the  processes  connected  with  model  making  no  matter  what  their  standing. 
This  book  will  help  you  to  become  a  better  mechanic.  It  is  full  of  suggestions  for  those 
who  like  to  make  things,  amateur  and  professional  alike.  It  has  been  prepared  es- 
pecially for  men  with  mechanical  hobbies.  Some  may  be  engineers,  machinists,  jew- 
elers, pattern  makers,  office  clerks  or  bank  presidents.  Men  from  various  walks  of 
life  have  a  peculiar  interest  in  model  engineering.  MODEL  MAKING  will  be  a  help  and 
an  inspiration  to  such  men.  It  tells  them  "  how-to-do"  and  "how-to-make"  things* 
in  simple,  understandable  terms.  Not  only  this,  it  is  full  of  good,  clear  working 
drawings  and  photographs  of  the  models  and  apparatus  described.  Each  model  has 
been  constructed  and  actually  works  if  it  is  made  according  to  directions.  375  pages. 
300  illustrations.  Price $3.00 

MARINE  ENGINEERING 

THE   NAVAL  ARCHITECT'S   AND    SHIPBUILDER'S  POCKETBOOK.     Of 

Formulae,  Rules,  and  Tables  and  Marine  Engineer's  and  Surveyor's  Handy 
Book  of  Reference.  By  CLEMENT  MACKROW  and  LLOYD  WOOLLARD. 

The  eleventh  revised  and  enlarged  edition  of  this  most  comprehensive  work  has  just 
been  issued.  It  is  absolutely  indispensable  to  all  engaged  hi  the  Shipbuilding  Industry, 
as  it  condenses  into  a  compact  form  all  data  and  formulae|that  are  ordinarily  required. 
The  book  is  completely  up  to  date,  including  among  other  subjects  a  section  on 
Aeronautics.  750  pages,  limp  leather  binding.  Price $6.00 

MARINE  ENGINES  AND  BOILERS— THEIR  DESIGN  AND  CONSTRUC- 
TION. THE  STANDARD  BOOK.  By  DR.  G.  BAUER,  LESLIE  S.  ROBERTSON 
and  S.  BRYAN  DONKIN. 

In  the  words  of  Dr.  Bauer,  the  present  work  owes  its  origin  to  an  oft  felt  want  of  a 
condensed  treatise  embodying  the  theoretical  and  practical  rules  used  in  designing 
marine  engines  and  boilers.  The  need  of  such  a  work  has  been  felt  by  most  en- 
gineers engaged  hi  the  construction  and  working  of  marine  engines,  not  only  by  the 
younger  men,  but  also  by  those  of  greater  experience.  The  fact  that  the  original 
German  work  was  written  by  the  chief  engineer  of  the  famous  Vulcan  Works,  Stettin, 
is  in  itself  a  guarantee  that  this  book  is  in  all  respects  thoroughly  up-to-date,  and 

29 


CATALOGUE   OF   GOOD,  PRACTICAL  BOOKS 

that  it  embodies  all  the  information  which  is  necessary  for  the  design  and  construction 
of  the  highest  types  of  marine  onginc-s  and  boilers.  It  may  be  said  that  the  motive 
power  which  Dr.  Bauer  has  placed  in  the  fast  German  liners  that  have  been  turned 
out  of  late  years  from  the  Stettin  Works  represent  the  very  best  practice  in  marine 
engineering  of  the  present  day.  The  work  is  clearly  written,  thoroughly  systematic, 
theoretically  sound;  while  the  character  of  the  plans,  drawings,  tables,  and  statistics 
is  without  reproach.  The  illustrations  are  careful  reproductions  from  actual  working 
drawings,  with  some  well-executed  photographic  views  of  completed  engines  and 
boilers.  744  pages.  550  illustrations,  and  numerous  tables.  Cloth.  Price.  $10.00 

MODERN  SUBMARINE  CHART. 

A  cross-section  view,  showing  clearly  and  distinctly  all  the  interior  of  a  Submarine 
of  the  latest  type.  You  get  more  information  from  this  chart  about  the  construction 
and  operation  of  a  submarine  tha"n  in  any  other  way.  No  details  omitted — every- 
thing is  accurate  and  to  scale.  It  is  absolutely  correct  in  every  detail,  having  been 
approved  by  naval  engineers.  All  the  machinery  and  devices  fitted  in  a  modern 
Submarine  Boat  are  shown,  and  to  make  the  engraving  more  readily  understood 
all  the  features  are  shown  in  operative  form,  with  Officers  and  Men  in  the  act  of  per- 
forming thr  duties  assi-ncd  to  them  in  service'conditions.  THIS  CHART  IS  REALLY 
AN  ENCYCLOPEDIA  OF  A  SUBMARINE.  It  is  educational  and  worth  many 
times  its  cost.  Mailed  in  a  tube  for 25  cents 

MANUAL  TRAINING 

ECONOMICS  OF  MANUAL  TRAINING.    By  Louis  ROUILLION. 

The  only  book  published  that  gives  just  the  information  needed  by  all  interested  in 
Manual  Training,  regarding  Buildings,  Equipment,  and  Supplies.  Shows  exactly 
what  is  needed  for  all  grades  of  the  work  from  the  Kindergarten  to  the  High  and 
Normal  School.  Gives  itemized  lists  of  everything  used  in  Manual  Training  Work 
and  tells  just  what  it  ought  to  cost.  Also  shows  where  to  buy  supplies,  etc.  Contains 
174  pages,  and  is  fully  illustrated.  2d  edition.  Price $2.00 

MINING 


ORE  DEPOSITS,  WITH  A  CHAPTER  ON  HINTS  TO  PROSPECTORS. 
By  J.  P.  JOHNSON. 

This  book  gives  a  condensed  account  of  the  ore  deposits  at  present  known  in  South 
Africa.  It  is  also  intended  as  a  guide  to  the  prospector.  Only  an  elementary  knowl- 
edge of  grology  and  some  mining  experience  are  necessary  in  order  to  understand  this 
work.  With  these  qualifications,  it  will  materially  assist  one  in  his  search  for  me- 
talliferous mineral  occurrences  and,  so  far  as  simple  ores  are  concerned,  should  enable 
one  to  form  some  idea  of  the  possibilities  of  any  he  may  find.  Illustrated. 
Cloth.  Price $2.00 

PRACTICAL  COAL  MINING.    By  T.  H.  COCKIN. 

An  important  work,  containing  428  pages  and  213  illustrations,  complete  with  practical 
details,  which  will  intuitively  impart  to  the  reader  not  only  a  general  knowledge  of  the 
principles  of  coal  mining,  but  also  considerable  insight  into  allied  subjects.  The 
treatise  is  positively  up-to-date  in  every  instance,  and  should  be  in  the  hands  of  every 
colliery  engineer,  geologist,  mine  operator,  superintendent,  foreman,  and  all  others 
who  are  interested  in  or  connected  with  the  industry.  Third  edition  .  .  $2.50 

PHYSICS  AND  CHEMISTRY  OF  MINING.    By  T.  H.  BYROM. 

A  practical  work  for  the  use  of  all  preparing  for  examinations  in  mining  or  qualifying 
for  colliery  managers'  certificates.  The  aim  of  the  author  in  this  excellent  book  is 
to  place  clearly  before  the  reader  useful  and  authoritative  data  which  will  render  him 
valuable  assistance  in  his  studies.  The  only  work  of  its  kind  published.  The  in- 
formation incorporated  in  it  will  prove  of  the  greatest  practical  utility  to  students, 
mining  engineers,  colliery  managers,  and  all  others  who  are  specially  interested  in  the 
present-day  treatment  of  mining  problems.  Second  edition,  revised.  188  pages. 
Illustrated:  Price  ...... $2.00 

30 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 


PATTERN  MAKING 

PRACTICAL  PATTERN  MAKING.    By  F.  W.  BARROWS. 

This  book,  now  in  its  second  edition,  is  a  comprehensive  and  entirely  practical  treatise 
on  the  subject  of  pattern  making,  illustrating  pattern  work  in  both  wood  and  metal, 
and  with  definite  instructions  on  the  use  of  plaster  of  paris  in  the  trade.  It  gives 
specific  and  detailed  descriptions  of  the  materials  used  by  pattern  makers  and  de- 
scribes the  tools,  both  those  for  the  bench  and  the  more  interesting  machine  tools; 
having  complete  chapters  on  the  Lathe,  the  Circular  Saw,  and  the  Band  Saw.  It  gives 
many  examples  of  pattern  work,  each  one  fully  illustrated  and  explained  with  much 
detail.  These  examples,  in  their  great  variety,  offer  much  that  will  be  found  of 
interest  to  all  pattern  makers,  and  especially  to  the  younger  ones,  who  are  seeking 
information  on  the  more  advanced  branches  of  their  trade. 

In  this  second  edition  of  the  work  will  be  found  much  that  is  new,  even  to  those  who 
have  long  practised  this  exacting  trade.  In  the  description  of  patterns  as  adapted 
to  the  Moulding  Machine  many  difficulties  which  have  long  prevented  the  rapid  and 
economical  production  of  castings  are  overcome;  and  this  great,  new  branch  of  the 
trade  is  given  much  space.  Stripping  plate  and  stool  plate  work  and  the  less  expen- 
sive vibrator,  or  rapping  plate  work,  are  all  explained  in  detail. 

Plain,  everyday  rules  for  lessening  the  cost  of  patterns,  with  a  complete  system  of 
cost  keeping,  a  detailed  method  of  marking,  applicable  to  all  branches  of  the  trade, 
with  complete  information  showing  what  the  pattern  is,  its  specific  title,  its  cost, 
date  of  production,  material  of  which  it  is  made,  the  number  of  pieces  and  core- 
boxes,  and  its  location  in  the  pattern  safe,  all  condensed  into  a  most  complete  card 
record,  with  cross  index. 

The  book  closes  with  an  original  and  practical  method  for  the  inventory  and  valua- 
tion of  patterns.  Containing  nearly  350  pages  and  1 70  illustrations.  Price.  $2.5O 

PERFUMERY 

PERFUMES  rAND  COSMETICS,  THEIR  PREPARATION  AND  MANUFAC- 
TURE.   By  G.  W.  ASKINSON,  Perfumer. 

A  comprehensive  treatise,  in  which  there  has  been  nothing  omitted  that  could  be  of 
value  to  the  perfumer  or  manufacturer  of  toilet  preparations.  Complete  directions 
for  making  handkerchief  perfumes,  smelling-salts,  sachets,  fumigating  pastilles; 
preparations  for  the  care  of  the  skin,  the  mouth,  the  hair,  cosmetics,  hair  dyes  and 
other  toilet  articles  are  given,  also  a  detailed  description  of  aromatic  substances ;  their 
nature,  tests  of  purity,  and  wholesale  manufacture,  including  a  chapter  on  synthetic 
products,  with  formulas  for  their  use.  A  book  of  general,  as  well  as  professional  in- 
terest, meeting  the  wants  not  only  of  the  druggist  and  perfume  manufacturer,  but 
also  of  the  general  public.  Among  the  contents  are:  1.  The  History  of  Perfumery. 
2.  About  Aromatic  Substances  in  General.  3.  Odors  from  the  Vegetable  Kingdom. 
4.  The  Aromatic  Vegetable  Substances  Employed  in  Perfumery-  5.  The  Animal  Sub- 
stances Used  in  Perfumery.  6.  The  Chemical  Products  Used  in  Perfumery.  7.  The  Ex- 
traction of  Odors.  8.  The  Special  Characteristics  of  Aromatic  Substances.  9.  The  Adul- 
teration of  Essential  Oils  and  Their  Recognition.  10.  Synthetic  Products.  11.  Table  of 
Physical  Properties  of  Aromatic  Chemicals.  12.  The  Essences  or  Extracts  Employed 
in  Perfumery-  13.  Directions  for  Making  the  Most  Important  Essences  and  Extracts. 
14.  The  Division  of  Perfumery.  15.  The  Manufacture  of  Handkerchief  Perfumes. 
16.  Formulas  for  Handkerchief  Perfumes.  17.  Ammoniacal  and  Acid  Perfumes. 
18.  Dry  Perfumes.  19.  Formulas  for  Dry  Perfumes.  20.  The  Perfumes  Used  for 
Fumigation.  21.  Antiseptic  and  Therapeutic  Value  of  Perfumes.  22.  Classification  of 
Odors.  23.  Some  Special  Perfumery  Products.  24.  Hygiene  and  Cosmetic  Perfumery. 
25.  Preparations  for  the  Care  of  the  Skin.  26.  Manufacture  of  Casein.  27.  Formulas 
for  Emulsions.  28.  Formulas  for  Cream.  29.  Formulas  for  Meals,  Pastes  and  Vege- 
table Milk.  30.  Preparations  Used  for  the  Hair.  31.  Formulas  for  Hair  Tonics  and 
Restorers.  32.  Pomades  and  Hair  Oils.  33.  Formulas  for  the  Manufacture  of 
Pomades  and  Hair  Oils.  34.  Hair  Dyes  and  Depilatories.  35.  Wax  Pomades,  Bando- 
lines and  Brilliantines.  36.  Skin  Cosmetics  and  Face  Lotions.  37.  Preparations  for 
the  Nails.  38.  Water  Softeners  and  Bath  Salts.  39.  Preparations  for  the  Care  of  the 
Mouth.  40.  The  Colors  Used  in  Perfumery.  41.  The  Utensils  Used  in  the  Toilet. 
Fourth  edition  much  enlarged  and  brought  up-to-date.  Nearly  400  pages,  illus- 
trated. Price $5.0O 

WHAT  IS  SAID  OF  THIS  BOOK: 

"  The  most  satisfactory  work  on  the  subject  of  Perfumery  that  we  have  ever  seen. 
"  We  feel  safe  in  saying  that  here  is  a  book  on  Perfumery  that  will  not  disappoint  you, 
for  it  has  practical  and  excellent  formulae  that  are  within  your   ability  to  prepare 
readily. 

"  We  recommend  the  volume  as  worthy  of  confidence,  and  say  that  no  purchaser  will  be 
disappointed  in  securing  from  its  pages  good  value  for  its  cost,  and  a  large  dividend 

31 


CATALOGUE   OF   GOOD,   PRACTICAL  BOOKS 

on  the  same,  even  if  he  should  use  but  one  per  cent  of  its  working  formulae.  There 
is  money  in  it  for  every  user  of  its  information." — Pharmaceutical  Record. 

HENLEY'S    TWENTIETH    CENTURY    BOOK    OF  RECIPES,  FORMULAS 
AND  PROCESSES.     Edited  by  G.  D.  Hiscox. 

The  most  valuable  techno-chemical  receipt  book  published.  Contains  over  10,000 
practical  receipts,  many  of  which  will  prove  of  special  value  to  the 
perfumer.  Price ....  $3.0O 

PLUMBING 


MECHANICAL  DRAWING  FOR  PLUMBERS.    By  R.  M.  STARBUCK. 


comprehensive  and  practical  treatise  on  the  subject  of  mechanical  drawing 
ous  modern  applications  to  the  work  of  all  who  are  in  any  way  connected 


vauons  01  separate  parts  01  me  piumoing  system.  ID.  juevauons  iroin  me  arcruiect  s 
plans.  17.  Drawings  of  detail  plumbing  connections.  18.  Architect's  plans  and  plumb- 
ing elevations  of  residence.  19.  Plumbing  elevations  of  residence  (continued) ;  plumb- 
ing plans  for  cottage.  20.  Plumbing  elevations;  roof  connections.  21.  Plans  and 


A  concise, 
in  its  variot 

with  the  plumbing  trade.  Nothing  will  so  help  the  plumber  in  estimating  and  in 
explaining  work  to  customers  and  workmen  as  a  knowledge  of  drawing,  and  to  the 
workman  it  is  of  inestimable  value  if  he  is  to  rise  above  his  position  to  positions  of 
greater  responsibility.  Among  the  chapters  contained  are:  1.  Value  to  plumber  of 
knowledge  of  drawing;  tools  required  and  their  use;  common  views  needed  in  mechan- 
ical drawing.  2.  Perspective  versus  mechanical  drawing  in  showing  plumbing  con- 
struction. 3.  Correct  and  incorrect  methods  in  plumbing  drawing;  plan  and  elevation 
explained.  4.  Floor  and  cellar  plans  and  elevation;  scale  drawings;  use  of  triangles. 
5.  Use  of  triangles ;  drawing  of  fittings,  traps,  etc.  6.  Drawing  plumbing  elevations 
and  fittings.  7.  Instructions  in  drawing  plumbing  elevations.  8.  The  drawing  of 
plumbing  fixtures;  scale  drawings.  9.  Drawings  of  fixtures  and  fittings.  10.  Inking 
of  drawings.  11.  Shading  of  drawings.  12.  Shading  of  drawings.  13.  Sectional 
drawings ;  drawing  of  threads.  14.  Plumbing  elevations  from  architect's  plan.  15.  Ele- 
vations of  separate  parts  of  the  plumbing  system.  16.  Elevations  from  the  architect's 
plans, 
ing  ele 

ing  plans  for  cottage.  20.  Plumbing 
plumbing  elevations  for  six-flat  building.  22.  Drawing  of  various  parts  of  the  plumb- 
ing system;  use  of  scales.  23.  Use  of  architect's  scales.  24.  Special  features  in  the 
illustrations  of  country  plumbing.  25.  Drawing  of  wrought-iron  piping,  valves,  radia- 
tors, coils,  etc.  26.  Drawing  of  piping  to  illustrate  heating  systems.  150  illustrations. 
Price .  . $2.00 

MODERN  PLUMBING  ILLUSTRATED.    By  R.  M.  STARBUCK. 

This  book  represents  the  highest  standard  of  plumbing  work.  It  has  been  adopted 
and  used  as  a  reference  book  by  the  United  States  Government,  in  its  sanitary  work  in 
Cuba,  Porto  Rico,  and  the  Philippines,  and  by  the  principal  Boards  of  Health  of  the 
United  States  and  Canada. 

It  gives  connections,  sizes  and  working  data  for  all  fixtures  and  groups  of  fixtures.  It 
is  helpful  to  the  master  plumber  in  demonstrating  to  his  customers  and  in  figuring 
work.  It  gives  the  mechanic  and  student  quick  and  easy  access  to  the  best  modern 
plumbing  practice.  Suggestions  for  estimating  plumbing  construction  are  contained 
in  its  pages.  This  book  represents,  in  a  word,  the  latest  and  best  up-to-date  practice 
and  should  be  in  the  hands  of  every  architect,  sanitary  engineer  and  plumber  who 
wishes  to  keep  himself  up  to  the  minute  on  this  important  feature  of  construction. 
Contains  following  chapters,  each  illustrated  with  a  full-page  plate:  Kitchen  sink, 
laundry  tubs,  vegetable  wash  sink;  lavatories,  pantry  sinks,  contents  of  marble  slabs; 
bath  tub,  foot  and  sitz  bath,  shower  bath ;  water  closets,  venting  of  water  closets ;  low- 
down  water  closets,  water  closets  operated  by  flush  valves,  water  closet  range ;  slop  sink, 
urinals,  the  bidet;  hotel  and  restaurant  sink,  grease  trap;  refrigerators,  safe  wastes,  laun- 
dry waste,  lines  of  refrigerators,  bar  sinks,  soda  fountain  sinks;  horse  stall,  frost-proof 
water  closets;  connections  for  S  traps,  venting;  connections  for  drum  traps;  soil  pipe 
connections;  supporting  of  soil  pipe;  main  trap  and  fresh  air  inlet;  floor  drains  and 
cellar  drains,  subsoil  drainage;  water  closets  and  floor  connections;  local  venting; 
connections  for  bath  rooms;  connections  for  bath  rooms,  continued;  connections  for 
bath  rooms,  continued;  connections  for  bath  rooms,  continued;  examples  of  poor 
practice;  roughing  work  ready  for  test?;  testing  of  plumbing  system;  method  of  con- 
tinuous venting;  continuous  venting  for  two-floor  work;  continuous  venting  for  two 
lines  of  fixtures  on  three  or  more  floors;  continuous  venting  of  water  closets;  plumb- 
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schools,  factories,  etc.;  use  of  flushing  valves;  urinals  for  public  toilet  rooms;  the 
Durham  system,  the  destruction  of  pipes  by  electrolysis;  construction  of  work  without 

32 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 

use  of  lead;  automatic  sewage  lift;  automatic  sump  tank;  country  plumbing;  construc- 
tion of  cesspools ;  septic  tank  and  automatic  sewage  siphon ;  country  plumbing ;  water 
supply  for  country  house;  thawing  of  water  mains  and  service  by  electricity;  double 
boilers;  hot  water  supply  of  large  buildings:  automatic  control  of  hot  water  tank;  sug- 
gestion for  estimating  plumbing  construction.  407  octavo  pages,  fully  illustrated  by  58 
full-page  engravings.  Third,  revised  and  enlarged  edition  just  issued.  Price  .  $.500 

STANDARD  PRACTICAL  PLUMBING.    By  R.  M.  STARBUCK. 

A  complete  practical  treatise  of  450  pages  covering  the  subject  of  Modern  Plumbing 
in  all  its  branches,  a  large  amount  of  space  being  devoted  to  a  very  complete  and 
practical  treatment  of  the  subject  of  Hot  Water  Supply  and  Circulation  and  Range 
Boiler  Work.  Its  thirty  chapters  include  about  every  phase  of  the  subject  one  can 
think  of,  making  it  an  indispensable  work  to  the  master  plumber,  the  journeyman 
plumber,  and  the  apprentice  plumber,  containing  chapters  on:  the  plumber's  tools; 
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traps;  venting;  continuous  venting;  house  sewer  and  sewer  connections;  house  drain; 
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water  for  large  buildings;  water  lift  and  its  use;  multiple  connections  for  hot  water 
boilers;  heating  of  radiation  by  supply  system;  theory  for  the  plumber;  drawing  for 
the  plumber.  Fully  illustrated  by  347  engravings.  Price S3. 50 


RECIPE  BOOK 

HENLEY'S  TWENTIETH  CENTURY  BOOK  OF  RECIPES,  FORMULAS  AND 
PROCESSES.    Edited  by  GARDNER  D.  Hiscox. 

The  most  valuable  Techno-chemical  Formula  Book  published,  including  over  10,000 
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"Your  Twentieth  Century  Book  of  Recipes,  Formulas,  and  Processes  duly  received. 
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Window, 

33 


CATALOGUE   OF   GOOD,  PRACTICAL  BOOKS 

"  I  purchased  your  book  '  Henley's  Twentieth  Century  Book  of  Recipes,  Formulas  and 
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Ohio. 

RUBBER 

RUBBER  HAND  STAMPS  AND  THE  MANIPULATION  OF  INDIA  RUBBER. 
By  T.  O'CoNOR  SLOANE. 

This  book  gives  full  details  on  all  points,  treating  in  a  concise  and  simple  manner  the 
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tions, Cements,  Blackings,  Renovating  Varnish,  and  Treatment  for  India  Rubber 
Shoes,  etc.  ;•  the  Hektograph  Stamp  Inks,  and  Miscellaneous  Notes,  with  a  Short 
Account  of  the  Discovery,  Collection  and  Manufacture  of  India  Rubber,  are  set  forth 
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Including  a  chapter  on  Rubber  Tire  Making  and  Vulcanizing;  also  a  chapter  on  the 
uses  of  rubber  in  Surgery  and  Dentistry.  Third  revised  and  enlarged  edition.  175 
pages.  Illustrated $1.25 

HENLEY'S  TWENTIETH  CENTURY  BOOK  OF  RECIPES,  FORMULAS 
AND  PROCESSES.  Edited  by  GARDNER  D.  Hiscox. 

Contains  upward  of  10,000  practical  receipts,  including  among  them  formulas  on 
artificial  rubber.  Price $3.0O 

SAWS 

SAW  FILINGS  AND  MANAGEMENT  OF*  SAWS.  By  ROBERT  GRIMSHAW. 
A  practical  hand-book  on  filing,  gumming,  swaging,  hammering,  and  the  brazing  of 
band  saws,  the  speed,  work,  .and  power  to  run  circular  saws,  etc.  A  handy  book  for 
those  who  have  charge  of  saws,  or  for  those  mechanics  who  do  their  own  filing,  as  it  deals 
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and  rules  for  gumming,  setting,  and  filing,  and  is  a  practical  aid  to  those  who  use  saws 
for  any  purpose.  Complete  tables  of  proper  shape,  pitch,  and  saw  teeth  as  well  as 
sizes  and  number  of  teeth  of  various  saws  are  included.  Fourth  edition,  revised  and 
enlarged.  Illustrated.  Price $1.25 

STEAM  ENGINEERING 

AMERICAN  STATIONARY  ENGINEERING.    By  W.  E.  CRANE. 

This  book  begins  at  the  boiler  room  and  takes  in  the  whole  power  plant.  A  plain 
talk  on  every-day  work  about  engines,  boilers,  and  their  accessories.  It  is  not  intended 
to  be  scientific  or  mathematical.  All  formulas  are  in  simple  form  so  that  any  one 
understanding  plain  arithmetic  can  readily  understand  any  of  them.  The  author 
has  made  this  the  most  practical  book  in  print;  has  given  the  results  of  his  years  of 
experience,  and  has  included  about  all  that  has  to  do  with  an  engine  room  or  a  power 
plant.  You  are  not  left  to  guess  at  a  single  point.  You  are  shown  clearly  what  to 
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ing "shut  downs"  and  repairs:  in  short,  all  that  goes  to  make  up  the  requirements 
of  a  good  engineer,  capable  of  taking  charge  of  a  plant.  It's  plain  enough  for  practical 
men  and  yet  of  value  to  those  high  in  the  profession. 

34 


CATALOGUE   OF  GOOD,  PRACTICAL  BOOKS 

A  partial  list  of  contents  is:  The  boiler  room,  cleaning  boilers,  firing,  feeding;  pumps, 
inspection  and  repair;  chimneys,  sizes  and  cost;  piping;  mason  work;  foundations; 
testing  cement;  pile  driving;  engines,  slow  and  high  speed;  valves;  valve  setting; 
Corliss  engines,  setting  valves,  single  and  double  eccentric;  air  pumps  and  condensers: 
different  types  of  condensers;  water  needed;  lining  up;  pounds;  pins  not  square  in 
crosshead  or  crank;  engineers'  tools;  pistons  and  piston  rings;  bearing  metal; 'hard- 
ened copper;  drip  pipes  from  cy Under  jackets;  belts,  how  made,  care  of;  oils;  greases; 
testing  lubricants;  rules  and  tables,  including  steam  tables;  areas  of  segments; 
squares  and  square  roots;  cubes  and  cube  root;  areas  and  circumferences  of  circles. 
Notes  on:  Brick  work;  explosions;  pumps;  pump  valves;  heaters,  economizers; 
safety  valves;  lap,  lead,  and  clearance.  Has  a  complete  examination  for  a  license, 
etc.,  etc.  Second  edition.  285  pages.  Illustrated.  Price $2 .50 

ENGINE  RUNNER'S  CATECHISM.    By  ROBERT  GRIMSHAW. 

A  practical  treatise  for  the  stationary  engineer,  telling  how  to  erect,  adjust,  and  run 
the  principal  steam  engines  in  use  in  the  United  States.  Describing  the  principal 
features  of  various  special  and  well-known  makes  of  engines:  Temper  Cut-off,  Shipping 
and  Receiving  Foundations,  Erecting  and  Starting,  Valve  Setting,  Care  and  Use, 
Emergencies,  Erecting  and  Adjusting  Special  Engines. 

The  questions  asked  throughout  the  catechism  are  plain  and  to  the  point,  and  the 
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the  instructions  given  are  complete  and  up-to-date;  and  they  are  written  in  a  popular 
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compass.  387  pages.  Seventh  edition.  Price $2.00 

HORSE-POWER  CHART. 

Shows  the  horse-power  of  any  stationary  engine  without  calculation.  No  matter  what 
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saves  time  and  calculations.  Especially  useful  to  engineers  and  designers.  50  cents 

MODERN   STEAM   ENGINEERING   IN   THEORY   AND    PRACTICE.    By 
GARDNER  D.  Hiscox. 

This  is  a  complete  and  practical  work  issued  for  Stationary  Engineers  and  Firemen, 
dealing  with  the  care  and  management  of  boilers,  engines,  pumps,  superheated  steam, 
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branches  with  which  the  modern  engineer  must  be  familiar.  Nearly  200  questions  with 
their  answers  on  steam  and  electrical  engineering,  likely  to  be  asked  by  the  Examin- 
ing Board,  are  included. 

Among  the  chapters  are:  Historical:  steam  and  its  properties;  appliances  for  the 
generation  of  steam;  types  of  boilers;  chimney  and  its  work;  heat  economy  of  the 
feed  water;  steam  pumps  and  their  work;  incrustation  and  its  work;  steam  above 
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elevators  and  their  management;  cost  of  power;  steam  engine  troubles;  electric 
power  and  electric  plants.  487  pages.  405  engravings.  3d  Edition.  .  .  .  $3.50 

STEAM  ENGINE  CATECHISM.    By  ROBERT  GRIMSHAW. 

This  unique  volume  of  413  pages  is  not  only  a  catechism  on  the  question  and  answer 
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STEAM  ENGINEER'S  ARITHMETIC.    By  COLVIN-CHENET. 

A  practical  pocket-book  for  the  steam  engineer.  Shows  how  to  work  the  problems  of 
the  engine  room  and  shows  "why."  Tells  how  to  figure  horsepower  of  engines  ana 
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the  easiest.  Second  Edition 60  centi 

35 


CATALOGUE   OF   GOOD,  PRACTICAL  BOOKS 

STEAM  ENGINE  TROUBLES.     By  H.  HAMKENS. 

It  is  safe  to  say  that  no  book  has  ever  been  published  which  gives  the  practical  en- 
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tells  how  to  remedy  them.  350  pages.  276  illustrations.  Price  ....  $2.50 

BOILER  ROOM  CHART.     By  GE^.  L.  FOWLER. 

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STEAM  HEATING  AND  VENTILATION 

PRACTICAL  STEAM,  HOT- WATER  HEATING  AND  VENTILATION.    By 
A.  G.  KING. 

This  book  is  the  standard  and  latest  work  published  on  the  subject  and  has  been  pre- 
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500  PLAIN  ANSWERS  TO  DIRECT  QUESTIONS  ON  STEAM,  HOT-WATER, 
VAPOR  AND  VACUUM  HEATING  PRACTICE.  By  ALFRED  G.  KING. 
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ever  been  published.  It  answers  all  the  questions  regarding  each  method  or  system 
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text  or  reference  book,  and  for  examination  questions  by  Trade  Schools  or  Steam 
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Heat.  Methods  of  Heating.  Chimneys  and  Flues.  Boilers  for  Heating.  Boiler 
Trimmings  and  Settings.  Radiation.  Steam  Heating.  Boiler,  Radiator  and  Pipe 
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Vacuum  Vapor  and  Vacuo- Vapor  Heating.  Mechanical  Systems  of  Vacuum  Heating. 
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36 


CATALOGUE   OF   GOOD,  PRACTICAL  BOOKS 


STEEL 


STEEL:  ITS  SELECTION,  ANNEALING,  HARDENING,  AND  TEMPERING. 


By  E.  R.  MARKHAM. 
This 


This  work  was  formerly  known  as  "The  American  Steel  Worker,"  but  on  the  pub- 
lication of  the  new,  revised  edition,  the  publishers  deemed  it  advisable  to  change  its 
title  to  a  more  suitable  one.  It  is  the  standard  work  on  Hardening,  Tempering, 
and  Annealing  Steel  of  all  kinds. 

This  book  tells  how  to  select,  and  how  to  work,  temper,  harden,  and  anneal  steel  for 
everything  on  earth.  It  doesn't  tell  how  to  temper  one  class  of  tools  and  then  leave 
the  treatment  of  another  kind  of  tool  to  your  imagination  and  judgment,  but  it  gives 
careful  instructions  for  every  detail  of  every  tool,  whether  it  be  a  tap,  a  reamer  or  just 
a  screw-driver.  It  tells  about  the  tempering  of  small  watch  springs,  the  hardening  of 
cutlery,  and  the  annealing  of  dies.  In  fact,  there  isn't  a  thing  that  a  steel  worker 
would  want  to  know  that  isn't  included.  It  is  the  standard  book  on  selecting,  harden- 
ing, and  tempering  all  grades  of  steel.  Among  the  chapter  headings  might  be  mentioned 
the  following  subjects:  Introduction;  the  workman;  steel;  methods  of  heating; 
heating  tool  steel;  forging;  annealing;  hardening  baths;  baths  for  hardening;  harden- 
ing steel;  drawing  the  temper  after  hardening;  examples  of  hardening;  pack  harden- 
ing; case  hardening;  spring  tempering;  making  tools  of  machine  steel;  special  steels; 
steel  for  various  tools;  causes  of  trouble;  high  speed  steels,  etc.  400  pages.  Very 
fully  illustrated.  Fourth  Edition.  Price $3.0O 

HARDENING,   TEMPERING,  ANNEALING,  AND  FORGING   OF  STEEL. 
By  J.  V.  WOODWORTH. 

A  new  work  treating  in  a  clear,  concise  manner  all  modern  processes  for  the  heating, 
annealing,  forging,  welding,  hardening,  and  tempering  of  steel,  making  it  a  book  of 
great  practical  value  to  the  metal-working  mechanic  in  general,  with  special  directions 
for  the  successful  hardening  and  tempering  of  all  steel  tools  used  in  the  arts,  including 
milling  cutters,  taps,  thread  dies,  reamers,  both  solid  and  shell,  hollow  mills,  punches 
and  dies,  and  all  kinds  of  sheet  metal  working  tools,  shear  blades,  saws,  fine  cutlery,  and 
metal  cutting  tools  of  all  description,  as  well  as  for  all  implements  of  steel  both  large 
and  small.  In  this  work  the  simplest  and  most  satisfactory  hardening  and  temper- 
ing processes  are  given. 

The  uses  to  which  the  leading  brands  of  steel  may  be  adapted  are  concisely  presented, 
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methods  for  the  hardening  and  tempering  of  special  brands. 

A  chapter  devoted  to  the  different  processes  for  case-hardening  is  also  included,  and 
special  reference  made  to  the  adaptation  of  machinery  steel  for  tools  of  various  kinds. 
Fourth  Edition.  288  pages.  201  illustrations.  Price $3.00 

TRACTORS 


THE  MODERN  GAS  TRACTOR.     By  Major  VICTOR  W.  PAGE. 

A  complete  treatise  describing  all  types  and  sizes  of  gasoline,  kerosene,  and  oil  tractors. 
Considers  design  and  construction  exhaustively,  gives  complete  instructions  for  care, 
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The  best  and  latest  work  on  farm  tractors  and  tractor  power  plants.  A  work  needed 
by  farmers,  students,  blacksmiths,  mechanics,  salesmen,  implement  dealers,  designers, 
and  engineers.  500  pages.  Nearly  300  illustrations  and  folding  plates.  Price  $2.50 

TURBINES 


MARINE  STEAM  TURBINES.  By  DR.  G.  BAUER  and  O.  LASCHE.  Assisted 
by  E.  LCDWIG  and  H.  VOGEL.  Translated  from  the  German  and  edited  by 
M.  G.  S.  SWALIX>W. 

The  book  is  essentially  practical  and  discusses  turbines  in  which  the  full  expansion  of 
steam  passes  through  a  number  of  separate  turbines  arranged  for  driving  two  or  more 
shafts,  as  in  the  Parsons  system,  and  turbines  in  which  the  complete  expansion  of 
steam  from  inlet  to  exhaust  pressure  occurs  in  a  turbine  on  one  shaft,  as  in  the  case 
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tion necessary  for  the  construction  of  steam  turbines,  hence  it  nils  a  want  which 
is  hardly  met  by  larger  and  more  theoretical  works.  Numerous  tables,  curves  and 
diagrams  will  be  found,  which  explain  with  remarkable  lucidity  the  reason  why 
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of  vacuum  on  steam  consumption  of  steam  turbines,  etc.  In  a  word,  the  very  in- 
formation which  a  designer  and  builder  of  steam  turbines  most  requires.  Large 
octavo,  214  pages.  Fully  illustrated  and  containing  18  tables,  including  an  entropy 
chart.  Price.net $4.00 

37 


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JUST  OFF  THE  PRESS— NEW  REVISED  EDITION 

Lathe  Design,  Construction, 
and  Operation 


with 


Practical   Examples  of  Lathe  Work 

By  OSCAR  E.  PERRIGO,  M.E. 

500  Pages  (6x9)    .  Cloth  Binding 

350  Detailed  Engravings  made  from  Special   Drawings 


Price  $3.OO 


c/4  new  revised  edition,  and  the  only  complete  American  work  on  the  sub- 
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others.  It  is  strictly  up-to-date  in  its  descriptions  and  illustrations. 

ETHE  history  and  the  relations  of  the  lathe  to  manufacturing  are  given;  also  a  description  of 
the  various  devices  for  feeds  and  thread  cutting  mechanisms  from  early  efforts  in  this  direction 
to  the  present  time.    Lathe  design  is  thoroughly  discussed,  including  back  gearing,  driving 
cones,  thread  cutting  gears,  and  all  the  essential  elements  of  the  modern  lathe.   The  classifica- 
tion of  lathes  is  taken  up,  giving  the  essential  differences  of  the  several  types  of  lathes,  including,  as 
is  usually  understood,  engine  lathes,  bench  lathes,  speed  lathes,  forge  lathes,  gap  lathes,  pulley  lathes, 
forming  lathes,  multiple-spindle  lathes,  rapid-reduction  lathes,  precision  lathes,  turret  lathes,  special 
lathes,  electrically  driven  lathes,  etc.    In  addition  to  the  complete  exposition  on  construction  and 
design,  much  practical  matter  on  lathe  installation,  care  and  operation  has  been  incorporated  in  the 
enlarged  1916  edition.    All  kinds  of  lathe  attachments  for  drilling,  milling,  etc.,  are  described  and 
complete  instructions  are  given  to  enable  the  novice  machinist  to  grasp  the  art  of  lathe  operation  as 
well  as  the  principles  involved  in  design.    A  number  of  difficult  machining  operations  are  described 
at  length  and  illustrated. 

CONTAINS  SPECIAL  CHAPTERS  ON: 

I.  History  of  the  Lathe  up  to  the  Introduction  of  Screw  Threads.  II.  The  Development  of  the 
Lathe  Since  the  Introduction  of  Screw  Threads.  III.  Classification  of  Lathes.  IV.  Lathe  Design— 
The  Bed  and  Its  Supports.  V.  Lathe  Design— The  Head-Stock  Casting,  the  Spindle  and  the  Spindle 
Cone.  VI.  Lathe  Design — The  Spindle  Bearings,  the  Back  Gears  and  the  Triple  Gear  Mechanism. 
VII.  Lathe  Design — The  Tail-Stock,  the  Carriage,  the  Apron,  etc.  VIII.  Lathe  Design — Turning 
Rests,  Supporting  Rests,  Shaft  Straighteners,  etc.  IX.  Lathe  Attachments.  X.  Rapid  Change  Gear  • 
Mechanisms.  XI.  Lathe  Tools,  High-Speed  Steel,  Speeds  and  Feeds,  Power  for  Cutting  Tools,  etc. 
XII.  Testing  a  Lathe.  XIII.  Lathe  Work.  XIV.  Lathe  Work  Continued.  XV.  Engine  Lathes. 
XVI.  Engine  Lathes  Continued.  XVII.  Heavy  Lathes.  XVIII.  High  Speed  Lathes.  XIX.  Special 
Lathes.  XX.  Regular  Turret  Lathes.  XXI.  Special  Turret  Lathes.  XXII.  ElectricaHy  Driven 
Lathes.  XXIII.  Practical  Instructions  on  Lathe  Operation. 

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author  has  mastere*1  his  subject. — Locomotive  Engineering. 

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Engineering  Newt. 


JUST     PUBLISHED 

Drop  Forging,  Die  Sinking 

and 

Machine  Forming  of  Steel 

By  JOSEPH  V.  WOODWORTH 

Author  of  "  Dies :    Their  Construction  and  Use,"  "  American  Tool 
Making  and  Interchangeable  Manufacturing,  etc." 

326  Pages  (6x9)  300  Illustrations  Cloth  Binding 

Price  $3.OO 

This  is  a  practical  treatise  on  the  hot  and  cold  machine  forming  of  steel 
and  iron  into  finished  shapes;  together  with  tools,  dies  and  machinery 
involved  in  the  manufacture  of  duplicate  forgings  and  interchangeable  hot 
and  cold  pressed  parts  from  bar  and  sheet  metal. 

A  COMPREHENSIVE  and  modern  book  on  Drop  Forging,  Die  Sinking,  etc.,  has  long  been 
/\  desired,  and  the  publishers  now  offer  such  a  volume  written  by  an  expert.  The  text  of  the 
•A^m.  treatise  is  concise;  technical  and  ambiguous  terms  have  been  replaced  by  practical  and 
familiar  shop  words;  and  all  the  illustrations  and  descriptions  are  plain  and  simple  to  under- 
stand. The  description  of  every  subject  and  method  involved  has  been  boiled  down  to  the 
simplest  and  fewest  words  possible;  so  that  the  "meat"  of  all  may  be  arrived  at  and  digested  in  the 
shortest  time  by  the  busy  men  of  metals  who  will  consult  its  pages,  which  contain  a  valuable  mine 
of  information  on  modern  shop  practice,  processes,  methods,  machines,  tools  and  details.  This  is  a 
useful  book  of  reference  and  one  worth  reading  from  cover  to  cover. 

THIS  EXCELLENT  TREATISE  IS  FULL  OF  FACTS  ON: 

Die  Sinking  and  Drop  Forging  Practice  and  Design  for  Modern  Forging,  Pressing  and  Stamping 
of  Duplicate  Parts — Die  Sinking  Methods,  Processes,  Machines  and  Tools — Drop  Forging  Dies, 
Their  Design,  Construction  and  Use  in  Drop  Hammer  and  Forging  Machine — Press  Forming  of 
Heavy  Hot  and  Cold  Stock  in  Dies — Drop  Forging  and  Hardening  Plants;  Their  Designs,  Funda- 
mental Conditions  and  Equipment  Involved  in  Their  Attainment — Steel  and  Iron,  Their  Treatment 
for  Twisting,  Reducing,  Forging  and  Working  in  Drop  Dies — Hot  Pressed  Steel  and  Iron  Parts; 
Their  Manufacture  and  Assembling  into  Finished  Products — Drop  Hammers,  Their  Development, 
Weights,  Foundations  and  Dies — Forging  Machine,  Steam  Hammer,  Bulldozer  and  Swaging  Machine 
Methods  and  Processes — Machine  Forging  wjtfc  Examples  of  Modern  Practice  and  Tools  Involved., 

WHAT  IS  SAID  OF  THIS  BOOK: 

The  author  is  to  be  commended  for  this  much  needed  work. — Engineering  Record. 
A  book  worth  reading  from  cover  to  cover. — American  Cutler. 
The  author's  style  is  clear  and  direct. — Engineering  News. 

This  book  is  written  from  a  thoroughly  practical  point  of  view  and  will  prove  extremely  use- 
ful.— Scientific  American. 

This  is  a  practical  treatise  by  a  practical  man  and  covers  many  phases  of  a  subject  upon  which 
there  has  thus  far  been  little  literature. — American  Metal  Market. 


JUST  PUBLISHED—  SIXTH  REVISED  EDITION 


Machine  Shop  Tools  and 
Shop  Practice 

Their  Construction,  Operation  and  Manipulation, 
Including  both  Hand  and  Machine  Tools 

By  W.  H.  VANDERVOORT,  M.  E. 
555  Pages  (6x9  K)  673  Illustrations  Cloth  Binding 

Price  $4.25 

entirely  new  and  fully  illustrated  work  describing  in  every  detail  the 
construction,  operation  and  manipulation  of  both  hand  and  machine  tools  : 
being  a  work  of  practical  instruction  in  all  classes  of  machine  shop  practice. 

A    BOOK  that  should  be  found  in  every  machine  shop.    Suppose  it  is  desired  to  know  how  to  cut 

/\     bevel  gears,  to  calculate  milling  machine  spirals  or  to  make  countershaft  calculatfons  ;  or  to  get 

/""%    information  about  tap  drill  sizes,  the  classification  of  files;  change  gear  calculations;  deep  hole 

drilling  ;  turning  tapers  ;  testing  lathes,  etc.  ;  or  any  one  of  the  numerous  questions  that  a  little 

information  might  be  desired  upon  occasionally  —  these  pages  will  be  found  to  contain  the  satisfactory 

answer.    The  book  has  numerous  tables,  and  in  addition  to  the  chapters  strictly  on  tools  are  several 

on  fastenings,  gearing,  belting,  shafting,  and  the  treatment  of  steel. 

The  work  is  logically  arranged;  the  various  hand  and  machine  tools  being  grouped  into  classes. 
and  description  of  each  is  given  in  proportion  to  their  relative  importance.  The  illustrations  repre- 
sent the  very  latest  tools  and  methods,  all  of  which  are  clearly  described.  Each  tool  is  considered 
from  the  following  points:  First  —  Its  construction  with  hints  as  to  its  manufacture.  Second  —  Ita 
operation,  proper  manipulation  and  care.  Third  —  Numerous  examples  of  work  performed. 

SPECIAL  CHAPTERS  ON 

/I.  The  Hammer  and  Cold  Chisel.  II.  The  File  and  Filing.  III.  Scrapers  and  Surface  Platea. 
IV.  Standards  of  Measures.  V.  Calipers.  VI.  Gauges  and  Indicators.  VII.  Rules,  Squares  and  other 
Small  Tools.  VIII.  Drills.  IX.  Reamers.  X.  Screw  Threads,  Tap  and  Dies.  XI.  Drill  and  Tap 
Holders.  XII.  Mandrels.  XIII.  The  Lathe.  XIV.  The  Lathe  in  Modified  Forms.  XV.  Lathe 
Tools.  XVI.  Chucks  and  Drivers  for  Lathe  Work.  XVII.  Lathe  Work  Between  Centers.  XVIH. 
Lathe  Work  on  Face  Plate  Chuck  and  Carriage.  XIX.  Boring  and  Turning  Mills.  XX.  Planing  and 
Shaping  Machines;  their  Tools  and  Attachments.  XXI.  Planer  and  Shaper  Work.  XXII.  The 
Slotting  Machine  and  Key  Seater.  XXIII.  Milling  Machines.  XXIV.  Milling  Machine  Cutters. 
XXV.  Milling  Machine  Work.  XXVI.  Gear  Cutters  and  Gear  Cutting.  XXVII.  Drilling  Machines 
and  Drilling  Work.  XXVIII.  Grinding  Machines.  XXIX.  Hardening  and  Tempering.  XXX. 
Fastening.  XXXI.  Gearing.  XXXII.  Belting  and  Transmission  Machinery.  XXXIII.  Miscel- 
laneous Shop  Equipment  and  Conveniences.  XXXIV.  Useful  Data  and  Tables. 

WHAT  A  CUSTOMER  SAID  OF  THIS  BOOK: 

***  I  am  just  in  receipt  of  the  book  "Modern  Machine  Shop  Tools"  by  Vandervoort.  I  am  very 
much  pleased  with  it.  It  is  a  masterpiece  on  the  machine  shop.  Comprehensive,  thorough  and  con- 
cise. It  is  a  decided  improvement  on  the  many  works  on  the  same  subject. 

(Signed)  E.  H.  WILMARTH, 
Instructor  in  Shop  Work,  Stout  Manual  Training  School. 

Menomonie.  Wis. 

This  book  is  strictly  up  to  date  in  all  respects  and  is  the  most  complete,  concise  and  useful  work 
ever  published  on  the  subject.  No  machinist  can  afford  to  be  without  this  book.—  Scientific  American. 


By  OSCAR  E.  PERRIGO,  M.E. 


101  Pages   (5^x8) 


Illustrated 


Cloth  Binding 


Price  $1.25 


cA  practical  book  for  every  designer,  draftsman,  and  mechanic 
interested  in  the  invention  and  development  of  the  devices  for 
feed  changes  on  the  different  machines  requiring  such  mechanism. 
All  the  necessary  information  on  this  subject  is  taken  up, 
analyzed,  classified,  sifted,  and  concentrated  for  the  use  of 
busy  men  who  have  not  the  time  to  go  through  the  masses  of 
irrelevant  matter  with  which  such  a  subject  is  usually  encum- 
bered and  select  such  information  as  will  be  useful  to  them. 

(HE  author  shows  the  beginning  of  this  class  of  devices,  how  they  were  developed  by  others, 
the  methods  of  their  working,  their  differences  from  others  designed  for  like  purposes,  and  in 
what  points  they  were  similar  to  other  devices  intended  to  effect  the  same  results.  All  their 
details  are  clearly  brought  out,  illustrated,  and  described  so  as  to  show  the  designer  and  the 
mechanic  just  the  points  they  want  to  know. 

It  shows  just  what  has  been  done,  how  it  has  been  done,  when  it  was  done,  and  who  did  it. 
It  saves  time  in  hunting  up  patent  records  and  re-inventing  old  devices. 

CONTENTS: 

Introduction — Some  Lathe  History — The  Change  Gear  Patents — Recent   Advances  in  the 
Invention  of  Change  Gear  Devices — Conclusion. 

Bevel  Gear  Tables 


66  Pages 


By  D.  Ag.  ENGSTROM 


Illustrated 


Price  $1.25 


Cloth  Binding 


A  BOOK  that  will  at  once  commend  itself  to  mechanics  and  drafts- 
men.  Does  away  with  all  the  trigonometry  and  fancy  figuring 
on  bevel  gears  and  makes  it  easy  for  anyone  to  lay  them  out  or 
make  them  just  right.  There  are  36  full  page  tables  that  show  every 
necessary  dimension  for  all  sizes  or  combinations  you're  apt  to 
need.  No  puz/ling  figuring  or  guessing.  Gives  placing  distance,  all  the 
angles  (including  cutting  angles) ,  and  the  correct  cutter  to  use.  A  copy 
of  this  prepares  you  for  anything  in  the  bevel  gear  line. 


CONTENTS: 

Tooth  Elements— Tooth  Elements  for  Diametrical  Pitches— Tooth  Elements  for  Circular 
Pitches — Table-Value  Reduced  for  Circular  Pitches — Construction  of  Bevel  Gears — Explanation  of 
Terms — Calculating  Bevel  Gears— Forms  of  Teeth  in  Bevel  Gears— How  Tables  are  to  be  Used — 
How  to  Use  Tables  When  Number  of  Teeth  is  Greater  than  Given  in  Tables,  Etc.,  Etc. 


WHAT  IS  SAID   OF  THIS  BOOK: 

For  draftsmen  and  others  having  much  to  do  with  bevel  gears  this  book  is  of  decided  value.— 
American  Machinist. 


SEVENTH  EDITION 


Machine  Shop 
Arithmetic 


131  Pages  (4x6) 


By  COLV1N-CHENEY 


Price  6O  Cents 


Cloth  Binding 


<HIS  is  an  arithmetic  of  the  things  you  have  to  do  with  daily.    It  tells  you  plainly  about:  How 
to  find  areas  of  figures — how  to  find  surface  or  volume  of  balls  or  spheres— handy  ways  for 


T! 
calculating  —  about  compound  gearing  —  cutting  screw  threads  on  any  lathe  —  drilling  for  taps  — 
speeds  of  drills,  taps,  emery  wheels,  grindstones,  milling  cutters,  etc.  —  all  about  the  Metric 
system  with  conversion  tables  —  properties  of  metals  —  strength  of  bolts  and  nuts  —  decimal  equivalent 
of  an  inch.    All  sorts  of  machine  shop  figuring  and  1001  other  things,  any  one  of  which  ought  to  be 
worth  more  than  the  price  of  this  book  to  you,  and  it  saves  you  the  trouble  of  bothering  the  boss. 

CHAPTERS  CONTAINED  ARE: 

Decimals.  Conventional  Rule  for  Square  Root.  Conventional  Rule  for  Cube  Root. 
Mensuration.  Rules  for  Selecting  Change  Gears  for  Screw  Cutting.  Depth  of  V  Threads. 
for  Taps.  Bolts  and  Nuts.  Speed  of  Pulleys  and  Gears.  Calculating  Speed  of  Milling 
Drills  or  Work.  Speeds  of  Drills  and  Taps.  Speeds  of  Grindstones.  Principles  of  Square  Root. 
Principles  of  Cube  Root.  Foundation  Principles.  Principles  of  Screen  Cutting.  Handy  Ways  for 
Calculating.  Allowances  for  Running  and  Force  Fits.  Metric  System  of  Measurements. 


Formulas. 
.  Drilling 
g  Cutters. 


Shop  Kinks 


By  ROBERT  GRIMSHAW 
400  Pages  (5x7  H)  224  Illustrations  Cloth  Binding 


SHOP 
KINKS 


Price  $3.OO 


A  most  useful  book  for  the  machinist,  containing  trade 
secrets  and  mechanical  shop  wrinkles. 


A  BOOK  entirely  different  from  any  other  book  on  machine  shop  practice.  Departing  from 
conventional  style,  the  author  avoids  universal  or  common  shop  usage  and  limits  his  work  to 
showing  special  ways  of  doing  things  better,  more  cheaply  and  more  rapidly  than  usual.  As 
a  result  the  advanced  methods  of  representative  establishments  of  the  world  arc  placed  at  the 
disposal  of  the  reader.  •—-•-"  •  • 


i  reader.     This  book  shows  the  proprietor  where  large  savings  are  possible,  and  how 
products  may  be  improved.    To  the  employee  it  holds  out  suggestions  that,  properly  applied,  will 
dvancement.     No  shop  can  afford  to  be  without  it.     It  bristles  with  valuable  wrinkles 


hasten  his  ac 


___________________    No  shop  can  __________  ____________    _.  ________  ______ 

and  helpful  suggestions.    It  will  benefit  all,  from  apprentice  to  proprietor.    Every  machinist,  at  any 
age,  should  study  its  pages. 

AMONG  THE  CONTENTS  ARE: 


Lathe  Speed;  Lead  Screw;  Grinding  Lathe  Centers  and  Spindles;  Cut-off  Centers;  Tube  Centers; 
Centers  Right  and  Wrong;  Testing  Centers;  Alignment  of  Centers;  Setting  Lathes;  Bell  Chucks: 
Spring  Chucks;  Milling  Vise;  Tool  Clamps;  Tool  Holders;  Gauges;  Center  Drilling:  Combination 


Drill  and  Countersink;  Center  Reamer;  Centering  Devices;  Chasing;  Curve  Boring;  Turret  Lathe 
Tools;  Special  Tool  Holder;  Squaring  Up  Connecting  Rods;  Turning  Vulcanized  Fibre;  Turning  and 
Key  Seating  Shafting;  Counterbalancing  Cranks;  Slide  Rest;  Making  Reamers;  Step  Reamer; 
Standard  and  Adjustable  Reamers;  Planers;  Quick  Return,  Open  Side  and  Holding  Work;  Planer 
Chucks;  Hollow  Planing  and  Large  Work;  Planer  Parallels  and  Gage  Blocks;  Cutting  Gears  on  Planer 
and  Slottor;  Boring  Cylinders  and  Large  Holes;  Boring  Bars;  Work  on  the  Drill  Press.  Clamping  Jig 
Mid  Clamps;  Starting  aiid  Centering  Drills;  Drilling  Hard  Steel;  Drilling  Glass;  Splicing  Drills,  etc. 


JUST  PUBLISHED 


FOURTH   EDITION,   REVISED  AND   ENLARGED 


Its   Selection,  Annealing,  Hardening 
and  Tempering 

By  E.   R.   MARKHAM 

400  Pages  (5x7  J^)  Cloth  Binding 

168  Specially  Prepared  Illustrations 

Price  $3.OO 


This  work  was  formerly  known  as  "THE  AMERICAN  STEEL  WORKER,"  but  on  the  pub- 
lication of  the  present  edition,  the  publishers  deemed  it  advisable  to  change  the  title  to  a  more  comprehensire 
3ne,  viz:  "Steel,  Its  Selection,  Annealing,  Hardening  and  Tempering." 


THIS  book  tells  how  to  select  and  to  know  the  steel  best  suited  to  various  purposes ;  gives  reasons 
for  the  different  steels ;  how  to  heat  in  the  making  of  everything  in  the  way  of  tools  made  from 
steel ;  how  to  proceed  in  the  making  of  taps,  reamers,  drills  and  milling  cutters ;  how  to  harden 
dies  and  punches  from  the  largest  to  the  smallest;  about  the  tempering  of  springs,  from  watch 
springs  up;  about  saws,  chisels,  and  other  wood- working  tools;  about  pack  and  case  hardening; 
how  to  anneal;  about  heating  apparatus,  the  kinds  to  use  for  the  best  results,  and  how  to  make  such 
heating  apparatus  right  at  home  if  it  becomes  necessary;  gives  formulas  for  mixtures  for  baths  for 
different  purposes,  and  gives  good  reasons  why  each  is  best  adapted  to  its  special  work.  In  fact, 
there  isn't  a  thing  that  a  steel  worker  would  want  to  know  that  isn't  included  within  its  pages. 

Mr.  Markham  has  been  selecting,  annealing,  hardening,  tempering  and  studying  steel  for  nearly 
thirty  years  and  is  still  at  it.  There's  a  reason  for  every  failure  you  have — and  a  remedy.  You'll 
find  them  both  in  this  book;  and  it  will  be  mighty  handy  to  have  a  copy  to  look  over  when  something 
goes  wrong  and  you  want  to  get  it  going  right  without  any  delay. 

There  are  new  Sections  on  High  Speed  Steels,  High  Carbon  Steel,  Electric  and  Salt  Bath  Furn- 
aces and  Ovens.  This  makes  the  book  more  valuable  than  ever.  A  copy  ought  to  be  in  the  hands  of 
every  wide  awake  mechanic  and  in  every  shop  library  in  the  country — and  it  will  be  when  its  value 
is  fully  realized.  Its  pages  are  full  of  practical  information  that  you  cannot  find  elsewhere. 

AMONG   SOME  OF  THE  SUBJECTS  TREATED  ARE 

The  Workman — Steel — Methods  of  Heating — Heating  Tool  Steel — Forging — Annealing — Hard- 
ening Baths — Baths  for  Hardening— Hardening  Steel — Drawing  the  Temper  after  Hardening — 
Examples  of  Hardening — Pack  Hardening — Case  Hardening — Spring  Tempering — Making  Tools  of 
Machine  Steel — Special  Steels — Steel  for  Various  Tools — Cases  of  Trouble — Welding — High  Speed 
Steels — High  Carbon  Steel — Electric  and  Salt  Bath  Furnaces  and  Ovens. 

WHAT  IS  SAID  OF  THIS  BOOK: 

We  are  glad  to  note  the  appearance  of  this  excellent  book.  No  tool  maker  or  steel  worker  can 
make  a  mistake  in  buying  a  copy  of  this  publication. — American  Machinist. 

Contains  400  pages  of  solid  information. — American  Blacksmith. 

Every  machine  shop  superintendent  and  tool-room  foreman  ought  to  possess  a  copy  of  this 
valuable  book,  and  engineers  in  charge  can  save  their  firms  money  by  circulating  it  in  their  work- 
shops where  fine  steel  tools  are  made. — The  Canadian  Engineer. 

All  who  are  interesteu  in  the  subject  should  secure  a  copy  of  this  work  and  from  it  learn  all 
that  is  to  be  known  regarding  steel  and  its  use. 

This  is  among  the  best  technical  books  published,  and  will  prove  a  valuable  aid  to  every  one 
who  has  anything  to  do  with  the  making  of  steel  for  any  purpose  whatever.— National  Builder. 


Practical  35  Cent  Books 


These  are  Monographs  in  which  thoroughly  practical  men  give  definite  in- 
formation about  the  particular  subject  with  which  they  are  familiar.  They 
are  full  of  just  the  practical  points  you  want  to  know;  they  are  well  printed 
and  bound  in  handsome  paper  covers. 

TURNING  AND  BORING  TAPERS 

By  Fred  H.  Colvin 
Associate  Editor  "American  Machinist" 

There  are  two  ways  to  turn  tapers;  the  right  way  and  one  other.  This  treatise  has  to  do  with 
the  right  way;  it  tells  you  how  to  start  the  work  properly,  how  to  set  the  lathe,  what  tools  to  use 
and  how  to  use  them,  and  forty  and  one  other  little  things  that  you  should  know.  Fourth  edition. 

Price  35  cents. 

DRAFTING  OF  CAMS 

By  Louis  Rouillion 


Every  mechanic  is  interested  in  Cams,  and  this  shows  just  how  to  lay  them  out  for  any  kind 
rork  you  may  have.  There  is  more  real  information  in  this  little  book  than  in  others  that  cost 
•e.  Third  edition Price  35  cents. 


THREADS  AND  THREAD  CUTTING 

By  Colvin-Stabel 

This  clears  up  many  of  the  mysteries  of  thread  cutting,  such  as  double  and  triple  threads,  internal 
threads,  catching  threads,  use  of  hobs,  etc.  Contains  a  lot  of  useful  hints  and  several  tables.  Third 
edition Price  35  cents. 

COMMUTATOR  CONSTRUCTION 

By  William  Baxter,  Jr. 

The  business  end  of  any  dynamo  or  motor  of  the  direct  current  type  is  the  commutator.  This 
book  goes  into  the  designing,  building,  and  maintenance  of  commutators;  shows  how  to  locate 
troubles  and  how  to  remedy  them;  everyone  who  fusses  with  dynamos  needs  this.  Price  35  cents. 

BRAZING  AND  SOLDERING 

By  James  F.  Hobart 
The  only  book  that  shows  you  just  how  to  handle  any 


along ;  tells  you  what  mixture  to  use,  how  to  make  a  furnace 
edition. 


WIRING  A  HOUSE 

By  Herbert  Pratt  . 

Shows  a  house  already  built;  tells  just  how  to  start  about  wiring  it;  where  to  begin;  what  wire 
to  use;  how  to  run  it  according  to  Insurance  Rules;  in  fact,  just  the  information  you  need.  Directions 
apply  equally  to  a  shop Price  35  cents. 

o  "D  T?  C*  T  A  T       f~\  T?  17  T?  1?  •      ^e  ^^  send  you  any  five  of  these  books, 
O  IT  .C;  L/  1  A  1-f      V^rrr/IX.       if  ordered  at  one  time,  on  receipt  of  $1.50. 


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405  Hilgard  Avenue,  Los  Angeles,  CA  90024-1388 

Return  this  material  to  the  library 

from  which  it  was  borrowed. 


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UNIVERSITY  OF  CALIFORNIA 
LIBRARY 

LOS  ANGELES,  CALIF. 


